LỚP 5 :PHẦN LỜI BÀI 1-7

BÀI 1     

Starry, do you remember she is movement measuring milk from the milk can?

You must see him using this like vessels with ?

These a very measures find out of capacity.

That is the amount of it with it can hold.

Let’s look at the vessels, the capacity of this vessel is 20ml.

The capacity of this vessel is 50ml. this vessel can hold a 100ml.

The capacity of this vessel is 500ml and this vessel has capacity of litre. Isn’t it interesting Starry!

Now let’s start learn how to convert litre into millilitre.

Q: Convert 2l into ml

Ans: You know that 1l equals 1000ml

So 2l equals 2 into 1000

That is 2000ml

So 2l equals 2000ml

Let’s try another example.

Q: Convert 9l into ml

Ans: Now, 1l equals 1000ml

So 9l equals 9 into 1000

Is 9000

So 9l equals 9000ml

Q: Convert 6l into ml

Ans: 1l equals 1000ml

So 6l equals 6 into 1000

That is 6000

6l equals 6000ml

Q: Now convert 3l into ml

Ans: 1l equals 1000ml

So 3l equals 3 into 1000

That is 3000

3l equals 3000ml

Good! You know it is extremely important to you standard unit for Measures of capacity of vessel.

BÀI 2

Starry surprise!!! It is cake can bit feel. Oh! You can smell it.

But you have a wait for an hour before you eat it.

Why do you keep looking at the clock Starry? Lesson is lengthy of time.

Don’t you know that 60 minutes make an hour?

I understand you have forgot time measurement.

Let’s me provide them with you. Here is clock, Starry!

As you know it a hand as a hour hand and a minute hand.

That keep turning twelfth a day, turning on the time.

Now, do you know. How many minutes make an hour, Starry? Yes, 60 minutes make an hour.

And how many hours are there in a day, Starry? Right, 24 hours make a day.

Q: Starry, if one hour has 60 minutes. How many minutes would be there in 2 hours?

Ans: we will have 2 multiply to by 60

2 = 120

.

So 2 hours will be equals 120 minutes.

Now, so birthday cake 3 hours baked. How many minutes would that be?

1 hour equals 60 minutes

So 3 hours will be 3 multiply by 60

.

3 hours equals 180 minutes.

The cake would take 180 minutes to bake. Since we know 24 hours make one day, Starry.

Let us find out how many hours are there in 2 days?

1 day equals 24 hours

2 days means 2 multiply by 24

with is = 48 hours

2 days has 48 hours

Starry, if you are told not to eat a cake for 3 days.

After how many hours would you be able to eat the cake?

It’s too thinking. Wait! I’m explain. How many hours in 3 days?

Now 1 days equals 24 hours

3 days means 3 multiply by 24

With is 72 hours.

You will be able to eat the cake 72 hours later. Now let provide what we have study

1 hour has ____ minutes

1 hour has 60 minutes

There are 120 minutes ___ hours

There are 120 minutes 2 hours

1 day has ___ hours

1 day has 24 hours

4 hours means ___ minutes

4 hours means 240 minutes

There are ___ hours in 2 days

There are 48 hours in 2 days

Now solve these problem.

Q: How many minutes in 5 hours?

Ans: 5 hours equals 5 multiply by 60

Wishes equals 300 minutes

Q: How many hours in 4 days?

Ans: 4 days equals 4 multiply by 24

Wishes 96 hours

Very good, Starry! You have know learn the unit for measuring time.

And now your cake is ready. You can eat it. Have fun!

BÀI 3

Starry, you know that gram is the standard unit of measuring weights.

Look at these weights in grams.

This is a 10g weight, is a 20g weight, this is a 50g weight, this is a 100g weight,

this is a 200g weight, this is a 500g weight, and look at this,

now Starry, here is really big weight, it is kilogram, this is a 1 kg weight.

All this weight are you to measures the weight of groceries, fruits, vegetables.

Let’s weight this bag of rice. Umm!         

When we place 250 gram weight on the other bag. The bag get balance.

Now 500 + 500 = 1000 gram

Oh Starry! So you want to one kilogram weight to weight the rice   bag.

Ok, let’s to with them. Look Starry! This rice bag weight is 1kg.

Hey Starry! You know what’s mean?

Right! It’s mean 1000 gram is same as 1 kg. So we can say 1kg =   1000 gram.

We can written a kilogram as “ kg” in short.

Now, let’s learn how to convert kilogram to gram.

Let’s convert 4 kg into grams

Now 1kg = 1000g

So 4kg = 1000 x 4

= 4000

So 4kg = 4000g

Easy! Let’s try another one. Let’s convert 7kg into grams

Now 1kg = 1000g

So 7kg = 1000 x 7

= 7000

So 7kg = 7000g

Now let’s provide how to convert kilograms to grams

Convert 2kg to gram

1 kg = 1000g

So 2kg = 1000 x 2

= 2000g

So 2kg = 2000g

Now convert 5kg into grams

1kg = 1000g

= 1000 x 5

= 5000

So 5kg = 5000g

Good! It’s fun when different of object with standard unit. I’m sure it!

BÀI 4

Hey Starry! Do you remember meter scale? Good!

We have learnt that the meter scale has 100 centimeters.

So we can say that 1 meter equals 100 centimeters.

Now Starry, if 1 meter has 100 centimeters.

How many centimeter in 2 meters? Ok, don’t worry, let’s find it together.

1 meter equals 100 centimeters

So 2 meter equals 100 into 2

With is equals 200 centimeters

Now, help me with this. How many centimeter in 4 meters?

How many centimeter in 1 meters. Starry?

Good, 1 meter equals 100 centimeters

So 4 meters equals 100 into 4

With is 400 centimeters.

Very good, Starry! You have learnt to convert meters into centimeters.

Now let’s do some activity.

Write the proper number in the empty spaces.

1. 3 meters equals ___ into ___

Equals ___ centimeters.

3 meters equals 3 into 100

Equals 300 centimeters.

2. 6 meters equals ___ into ___

Equals ___ centimeters       

6 meters equals 6 into 100

Equals 600 centimeters

3. ___ equals ___ into ___

Equals 700 centimeters

7 meters equals 7 into 100

Equals 700 centimeters

4. ___ equals ___ into___

Equals 900 centimeters

9 meter equals 9 into 100

Equals 900 centimeters

Let’s do another activity.

Write which unit that is, meter or centimeter should be used to measure the following lengths.

- Depth of a box

The unit used should be centimeter.

- Thickness of a door

The unit used should be centimeter

- Length of a saree

The unit used should be meter.

- Length of a notebook

The unit used should be centimeter.

- The height of a tower

The unit used should be meter.

BÀI 5

Starry, do you remember that we use the unit centimeter and millimeter for smaller distances?

But do you know how to measure distances that are really long?

Seeing distances between your house and the school or the distances between two cites.

You must know that although a meter is a greater unit than centimeter,

we cannot use unit “meter” to measure such long distances.

For this we have another bigger unit that is kilometer.

1 kilometer equals 1000 meters. Kilometer can be written in short as km.

Now let’s learn how to convert kilometers to meters.

Let’s convert 2 kilometers into meters.

Now 1km equals 1000m

So 2km equals 1000 into 2

With is 2000

So 2km equals 2000m

Q: Convert 6 kilometers into meters.

Ans: 1km equals 1000m

6km equals 1000 into 6

With is 6000m

So 6 kilometers equals 6000 meters.

Let’s provide what we have learn. 

Q: Convert 9 kilometers into meters

Ans: 1km equals 1000m

9km equals 1000 into 9

With is 9000m

So 9 kilometers equals 9000 meters.

Let’s solve another example.

Q: convert 3 kilometers into meters.

Ans: 1km equals 1000m

3km equals 1000 into 3

With is 3000m

So 3 kilometers equals 3000 meters.

Very good! So you must remember that for smaller distances we use the unit centimeters and meters.

But for longer distances we use the unit kilometer.     

BÀI 6

Hey Starry! We have learnt how to find the smaller and the bigger number.

But if three numbers are given then we have to find the smallest and the biggest number.

Let us first use the number-strip method.

Consider the numbers 5, 16, 11. Let us first circle these number on the number-strip.

Here is 5, 16, and 11. Which the number comes first on the number-strip, Starry?

Yes, the number 5 comes first on the number-strip, so number 5 is the smallest.

                                    

Number 16 comes last on the number-strip, hence number 16 is the biggest.

Which number is left, Starry? Yes, the number 11 is left.

11 comes between the numbers 5 and 16.

Do you understand, Starry? Ok, let’s solve the next example.

Out of 13, 3, and 8 which is the smallest and biggest number?

What do you do first, Starry? Yes, we shall first draw the number-strip.

Now let us circle the numbers. 13, 3, and 8. Observe the numbers carefully, Starry.

Which number comes first on the number-strip?

Yes, number 3 comes first on the number-strip. So 3 is the smallest number.

The number 13 comes last so it is the biggest number.

Number 8 will be in between the two numbers. Ok Starry.

Now look at the numbers circled in the given number-strip and fill in the boxes.

1. _____ is the number that comes first. Can you answer it Starry?

Yes, 14 is the number that comes first. So, 14 is the smallest number.

2. Number 22 comes ____ . Yeah, number 22 comes last. So, number 22 is the biggest number.

Let us now learn how to find the smallest and the biggest number by using the square of 100.

Look at the square of 100 Starry. Now look at these three numbers highlighted in the same column.

The numbers are 69, 62, and 65. Which number comes first in this column Starry?

Yeah, number 62 comes first, so 62 is the smallest number. Out of 69, 62, and 65.

The number 69 comes last. So, 69 is the biggest number. Isn’t it easy?

Let us solve the next example.

Find the smallest and the biggest number out of 47, 77, and 17. What do you observe Starry?

Yes, all the number 77, 47, and 17 are from the same row.

17 comes first, so 17 is the smallest number.

77 comes last, so 77 is the biggest number.

Now, will you be able to solve the next example?

Out of 45, 18, and 37 which is the smallest and the biggest number?

Hey, Starry see all these number are from different column.

Number 18 is from the column that comes first. So the number 18 is the smallest.

45 is from the column that comes last. So the number 45 is the biggest.

Here is one last example Starry. Which is the smallest number out of 71, 17, and 77?

Yeah, number 17 is the smallest as it comes in the column which comes first in the number square.

So Starry, you can use any method to find the smallest and biggest number.

BÀI 7

Starry, you have already studied about bigger numbers and smaller numbers.

 Let us do activity.

Find the biggest and the smallest number and fill the table.

Look Starry, in the first set of the number.

42 is the biggest number, and 15 is the smallest number.

In the second set, 71 is the biggest number, and 22 is the smallest number.

In the third set, 69 is the biggest number, and 36 is the smallest number. Good Starry!

Now telling me among 83, 314, and 9. Which is the biggest number and which is the smallest number?

              

You are right! 9 is a one digit number. 83 is two digit number, and 314 is three digit number.

So three number 314 is a biggest number, and one digit number 9 is smallest number.

Um, Starry! Now look at these numbers, they are all three digit number.

Do you remember how we find out the biggest and the smallest numbers?

Let us look at the digit and the hundred places?

In 412, the digit in the hundred places is 4. In 315, the digit in the hundred places is 3.

In 278, the digit in the hundred places is 2.

The digit 4 in the hundred places is greater than 3 and 2, and the digit 2 in the hundred places is smaller than 3 and 4.

And the biggest number is 412, and the smallest number is 278.

Hey Starry, look here the numbers are 151, 136, and 149.

How do you compare them Starry? All these number are 1 in the hundred places.

You are right! So we will observe the digit in the tens places.

Now help me out Starry. Compare 5, 3, and 4.

Which are in the tens places of these numbers?

Good! 5 is greater than 3 and 4, and 3 is smaller than 4 and 5.

So the biggest number is 151, and the smallest number is 136.

Now telling me the smallest and the biggest number. Out of 604, 607, and 601.

In all three numbers 6 is in the hundred places, and 0 is in the tens places.

So what shall you do, Starry? Yes, you are right.

We look at the digit in the unit places. Um, so all of 4, 7, and 1 which is in the unit places.

1 is the smallest, and 7 is the biggest digit.

So 607 is the biggest number, and 601 is the smallest number.

Good Starry! Now which of the numbers 304, 631, 150, and 269 is the biggest and smallest?

Good, 631 is the biggest number, and 150 is the smallest number.

Good! Let us do another activity. Write the biggest and the smallest of the following numbers.

In the first set, the biggest number is 312 and the smallest number is 6.

In the second set, the biggest number is 962, and the smallest number is 129.

In the third set, the biggest number is 728, and the smallest number is 243.

In the fourth set, the biggest number is 842, and the smallest number is 500.

Good! Now circle the smallest of these numbers.

In the first set 183 is the smallest number.

In the second set the smallest number is 444.

In the third set the smallest number is 101.

Now circle the biggest of these numbers.

In the first set the biggest number is 521.

In the second set the biggest number is 736.

In the third set the biggest number is 866.

Good! Now you know how to compare numbers and find the biggest and the smallest number from the set of number.

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LỚP 4: PHẦN LỜI BÀI 1-9

BÀI 1

Stary! There is a gift for you on the table.

Let’s open the wrapper and see what the gift is.

wow, it’s a clock.

Such a colorful clock.

Look Stary! This is the face of clock.

The face of clock shows number 1 to 12.

Just like our hands. The clock has 2 hands.

One hand is small and the other is big.

The small hand is called the hour hand.

The big hand is called the minute hand.

Both the hands, that is the hour hand and minute hand move in this direction only.

BÀI 2

Stary you have such a beautiful clock in your hand.

But why you look so sad.

Don’t you know how to tell the time?

Oh, don’t worry. I will teach you.

Telling the time when the minute hand is on 12.

Stary, look at your clock.

The minute hand is the big hand and the hour hand is the small hand.

the minute hand is on 12 and the hour hand is on 2.

So the time is 2 o’clock.

Now the minute hand is on 12 and the hour hand is on 6.

So the time is 6 o’clock.

Here the minute hand is on 12 but the hour hand is on 8,

so Stary the time now is 8 o’clock.

Let us do an interesting activity.

Look at the clock and write the time in the box

The time shows in the first clock is 3 o’clock.

The time shows in the second clock is 5 o’clock.

The time shows in the third clock is 7 o’clock.

The time shows in the fourth clock is 10 o’clock.

                                                

Telling the time when the minute hand is on 3.

Now let us learn how to tell the time when the minute hand is on 3.

In this clock the minute hand is on 3 and the hour hand has passed 1.

So we say that the time is a quarter past 1.

And in this clock the minute hand is on 3 but the hour hand has passed 6.

The time is a quarter past 6.

Here is another clock Stary.

The minute hand is on 3 but the hour hand has passed 8.

So the time is a quarter past 8.

Now, let us revision what we have learnt.

Look at the clock and write the time

The first clock shows a quarter past 11

The second clock shows a quarter past 12.

The third clock shows a quarter past 5.

The fourth clock shows a quarter past 9

Good! now match the time with the clock.

The first clock shows a quarter past 2

The second clock shows a quarter past 10

The third clock shows a quarter past 7

The fourth clock shows a quarter past 3

Revision

Let us revise how to tell the time when the minute hand is on 12 and when it is on 3.

Stary, write the time I showed by the clock.

2 o’clock, 8 o’clock, quarter past 6, quarter past 9.

Good, Stary! You have done a great job.

Now we learn how to tell the time when the minute hand is on 6

.

Look at the clock, Stary.

Here the minute hand is on 6 and the hour hand is between 2 and 3.

So we say that the time is haft past 2

Now, let us keep the minute hand on 6 and the hour hand is between 6 and 7.

Now the time is haft past 6.

Oh, stary! Now you have kept the minute hand is on 6 hour hand is between 10 and 11.

So the time is haft past 10.

Let us do an activity.

Let us do an activity.

Look at the clock and write the time.

The first clock shows haft past 8.

The second clock shows haft past 5

The third clock shows haft past 12.

The fourth clock shows haft past 9.

Now, let us do something interesting.

The cartoon Cyril begins at haft past 4

The cartoon Cyril ends at haft past 5

Children went out to play at haft past 3

Children returned from play at haft past 7.

Revision

Stary, come on, let us revise telling the time.

Write the time as shown by the clock.

Quarter past 4

Haft past 11

9 o’clock

Very good, Stary!

Now let us teach you how to read the time when the minute hand is on 9.

Telling the time when the minute hand is on nine.

Look at the clock, the minute hand is on 9 and the hour hand is between 12 and 1, but closer to 1.

The time is a quarter to 1.

Now the minute hand is on 9. And the hour hand is between 5 and 6.

So the time is a quarter to 6.

Look at the clock now.

Here again the minute hand is on 9 but the hour hand is between 11 and 12.

So the time is a quarter to 12.

Let us now revise what we have learnt.

Look at the clock and write the time.

The time on the first clock is a quarter to 8.

The time on the second clock is a quarter to 3.

The time on the third clock is a quarter to 12.

The time on the fourth clock is a quarter to 1.

BÀI 3

Stary I don’t believe this. You are still fast asleep.

Oh I understand, you have learnt to read the calendar and you know it’s a holiday.

But Stary, it’s a bright sunny day so wake up and I teach you something more about months of the year.

The months of the year can be followed either from Gregorian year or from India solar year.

But today I will teach you about the Gregorian year.

The first month of the Gregorian years is January. It has 31 days.

Next term is February with 28-29 days.

March is the third month of the year with 31 days.

The fourth month of the year is April with 30 days.

Then come May, the fifth month with 31 days.

Follow it by June, the sixth month with 30 days.

Now, July has 31 days.

August comes next, the eighth month with 31 days.

The ninth month of the year is September with 30 days.

October is then month with 31 days.

The 11th month of the year is November, with 30 days.

And Stary the last month of the year twelfth month is December with 31 days.

Now Stary you look confuse. You are wondering how do we remember with the month has 30 days and which has 31 days?

Don’t worry I have a simple form just for you. Repeat it with me and it will help you know the number of the days in each month.

30 day has September, April, June and November.

All the rest has 31 days.

Except February is alone which has 28 days clear and 29 in a leap year.

Now let us revise what we have studied:

- November has _____days.

- The 8th month of the Gregorian year is ______.

-The month that comes after April is _____.

- The 3rd month of the Gregorian year has _____ days.

- The month of the Gregorian year that have 31 days are ________________.

- The only month that has 28 days is ________.

Now what is that easy Stary . I’m happy. You have learnt the months of the Gregorian year .

BÀI 4

Stary! Why are you awake so early today?

Oh! You thought it’s a school day.

It's weekend Stary and you have a holiday.

You are upset on you? You didn’t know? But don’t you have a calendar which you.

A calendar does use what day of the month is it and the month of the year too.

What’s the problem? I understand. You don’t know how to read it.

Don’t worry, today we will learn how to read a calendar.

Here is a calendar.

Stary, which month of the year does it show you?

Right! It’s the month of August and the year is 2010.

Can you count the number of Saturday in this month Stary?

Yes, There are 4 Saturday in August.

Support I told you today was the 8th of August.

What day of the week would it be?

Exactly Stary the 8th of August is a Sunday and you have a holiday today.

Can you tell me what is the date in the third Wednesday of the month.

The third Wednesday of the month is the 18th . That is really fast Stary.

- And which is the day occurs 5 times in the month of August?

Sunday, Monday and Tuesday occur 5 times in the month of August.

- Stary, do you know what date does Sunday come?

Sunday come on the 1st, 8th, 15th, 22nd, 29th of the month.

- And this year Stary on which day does the independent day fall?

Yes Independent day falls on Sunday.

Now, that you have understood the calendar. Let us revise what we have learnt.

Looking at the calendar answer these questions. Let’s begin.

- The day on the first Saturday of the month is ___________.

- The 31st of the month is ___________.

- There are _________ Wednesday in August.

- The month of August has ___________days.

- The day on which Thursday come are __________.

Excellent Stary , Are you happy?         

Now you can sleep late on the holiday.

BÀI 5

Hey Stary! Look at what are the father and son doing?

Uh, they want to measure how long the pace of ribbon is.

                                             

Look at how are they measuring Stary?

They are using the span of their hand.

This is called a hand span.

Stary look! When the boy measures the length of the string it comes to eight hand-spans.

Whereas when the father measures it the length of the string is 5 hand- spans.

But it is the same string.     

So tell me why is there the different in this length?

The father and the son has different hand- span.

The father’s hands- pan is bigger than the son.

Now look at! What they have in their hands.

Oh! They are using a tape measuring on the same job.

Hey, look Stary!

Now both the tape measures show the same length. That is 120cm

Stary! We can also use a scale for the same purpose.

When length its measure using devices like a tape measure or scale.

We get the same measure.

No matter how measure is.

Let us see what are can be measured using a measuring scale or a tape measure.

We can measure the height of furniture or our height, the length and breadth of cloth or table, the deep of tank or vessel & the thickness of the book or a door or a table.

You can have a lot of fun measuring with the tape measure or scale. Those have fun!

BÀI 6

Hey Stary! I want to buy a new table cloth, the old one has been torn a little.

But I’m not sure how big the table cloth should be?

Hey! I have an idea.

We shall fisrt measure the length of the table and then I can get the table cloth of that size.

Stary ! we shall measure the length of the table with a span.

A span is formed when the fingers are spead out.

The length of this table is 7 spans.

Hey ! we can also measure the length of the table using an arm-length.

An arm –length is also known as a cubit?

                

Let’s measure the length of the table.

The length of the table is 3 arm lengths , 3 cubits.

Stary! Just like we use a span or an arm-length to measure the length.

we can also use the feet and pace for measuring the lengths.

Look at the picture shows here.

Ram is measing the length of his room using his foot.

the length of his room is 20 foot-lengths.

But stary! what if Ram had to measure the length of his garden.

Measuring the foot would take a long time.

So Ram measures the length of the garden with his pace.

It was 8 paces long.

Stary, can you think of any other ways in which we can measure the length ?

Yes, we can also measure the length using a pencil or a stick or a rod.

Stary! take a look at these 2 pictures.

In the 1st picture we see that the girl measured the length of the blackboard by using arm-lengths.

It lengths was 4 arm lengths.

In the 2nd pictures the teacher has measured the length of the same blackboard using her arm lengths.

Now the length of the blackboard is 3 arm lengths.

In the picture given here.

the length of the carpet was measured by the boy using his foot length.

The length was 12 foot lengths.

The same carpet was measured by the father using his foot length 

Now the length of the carpet was 9 foot lengths.

Can you tell Stary why is there a difference in the lengths of the same objects?

You are smart, Stary.

The number of arm-length or foot length counted by both the people   in each people is not the same because the length of their arm or feet is not the same .

Hey Stary,See here are some chart papers.

let’s measure the length of this chart paper using a ruler.

The length of the chart paper is 2 ruler lengths.

What’s happen Stary ?

you have already measured of the length of the chart paper using the same scale.

What answer did you get ? 2 ruler lengths.

That’s great !

So it mean if we measure the length of the object with the same instrument then the measure remain the same no matter who measure it.

Stary ! Let’s now find the length of these rod.

The rods have been labeled A, B, C, D to identify them.

Let’s use the scale again.

The length of the rod A is 2 ruler length .

Now let measure the length of rod B.

The length of the rod B is 2 ruler lengths.

What is the measure of the 3rd rod, Stary?

It looks smallest. Hey ! Its length is only 1 ruler length.

Now, let’s measure the last rod.

The length is equal to the length of the rod B . that is 3 ruler lengths.

Stary ,our rod A and rod B which rod has less length.

Yes, the length of rod A is less than the length of rod B.

Our rod D & C whose length is more?

yes, the length of rod D is more than the length of rod C.

Stary, Here are the name of some articles, you have to give the best possible method of measuring their lengths.

+ The first one is a book.

How we use measure in the length Stary?

yes, by using the span of your hand.

+ The height of cupboard is the best measure by an arm-length.

+ What about the length of the ground, Stary?

yes, we measure it by using the pace of the foot.

+ The last is the length of ribbon.

We can measure it using an arm-length.

BÀI 7

Hey stary! You are aware that we need a standard device or instrument for measurement?

To measure them we need advice call measuring scale.

Look at the scale. Do you note some marking and number on it Stary?

Yes, of course. There are number up to 15.

Each number shows the distance a centimetre.

For example     

0 to 1 : a centimetre

12 to 13 : a centimetre

And 5 to 6 is also a centimetre.

Stary, look closely! Do you see something else?

Right! There are smaller marking within each centimetre.

Come, let us count the small marking 1, 2, 3, 4, 5, 6, 7, 8, 9, 10.

Thus, each centimetre has 10 such small divisions.

Stary, each such small division is called a millimetre.

So, we can see that 1 centimetre has 10 millimetres.

Now if we have 2 centimetres. There will be 20 such small divisions.

So 2 centimeters will have 20 millimetres.

In the same manner 5 centimetres will be equal to 50 millimetres and 10 centimetres will be equal to 100 millimetres.

Centimetre and millimetre are written in short as ‘cm’ and ‘mm’.

so we can say 8cm is equal to 80mm.

Stary! We can measure smaller lengths using a measuring scale.

For example

The thickness of breadth of a notebook or length of craft paper.

Hey! Why have you brought that cloth. Oh, Stary!

We cannot measure the length of cloth using a measuring scale.

We need a meter scale for measure longer length- the meter scale .

Look at this scale Stary. This is a meter scale. Observe!

The last number show here is 100.

So there are 100 cm on it. So 1 meter contains 100 cm.

It will write meter in short as ‘m’.Then 1m equal 100cm.

What are you thinking of Stary. Oh you want to measure greater distances.

Greater distances!

Greater distance likes length of the room are measured using another instrument call a measuring tape.

This tape has length more than 1 meter.

So Millimetre, Centimetre,

Meter are standard units for measuring length by standard units.

It mean that anywhere you go these are the accepted units for measuring length

BÀI  8

Hey Stary! Look. Here is the box of pencils. There are 10 pencils in this box.

Let us form pairs. That is group of 2 pencils each for both of us .

Here it is 1st pair, 2nd pair, 3rd pair, 4th pair and 5th pair.

Is any pencil let behind Stary?

No? Stary! no pencil is let behind after making groups of 2 each from 10 pencils ,

so 10 is known as an even number.

Don’t you know we also need erasers along with these pencils?

Yes, see. I have got a box of erasers too.

But it has only 7 erasers. Let us see Stary! How many pairs are form.

Here are they 1st pair, 2nd pair, 3rd pair.

Look Stary !1 eraser is let by itself.

So we say that 7 is an odd number.

Stary, if one object is left over after pairing then the number of objects is odd.

If no object is left after pairing, then number of objects is even.

Look at this number Stary. Number from 1 to 20 is written in it.

Starting from 1 circle every odd number.

So let circle the number 1, 3, 5, 7, 9, 11, 13, 15, 17 &19 .

Stary! Can we form a pair with 1 object? you’re right we can’t form a pair with 1 object.

Now let us circle the next circle number that is 3.uhm.

Here is 3 chocolates, Stary! Can you form pair with it?

only 1 pair is formed , &1 chocolate is left by itself.

So Stary the 3 is an odd or even number? Yes, 3 is an odd number.

See Stary, the remaining circle number has been written here.

Consider the number 5. Let’s form the pairs of line.

Here 2 pairs are form and 1 line is left by itself.

What’s about the number 7 stary? Yes!

Here are 3 pairs are form and 1 line is left by itself.

Similarly we observe that is odd number 9, 11, 15,17& 19 .

1 line is left behind.

Can you tell me what is common in all the number?

Yes, all the number 1, 3, 5, 7, 9, 11, 13, 15, 17,19 are odd numbers.

Now Stary, list these number are not circle.

Yes, the numbers are 2, 4, 6, 8, 10, 12, 14, 16, 18, 20 .

How many pairs are form with 2 object, Stary? Yes, only 1 pair

.

Which is the next number, Stary? Yes, it is 4.

Let’s see ! what do we have here? Yes, here we have 4 crayons .

Can you tell me how many groups of 2 crayons will be form?

Yes, 2 pairs are form and no crayon is left by itself.

So we can say that 4 is an even number.

Hey! Stary, it’s time to look at the other number.

The number is written here is 6. let us form pairs with 6 sticks.

Can you count the number of pair Stary,

yes 3 pairs of sticks are formed and no stick is left behind.

so 6 is an even number.

Observe carefully! when we form pair of sticks with number 8, 10, 12, 14, 16, 18 and 20 no sticks are left behind.

So we now know that the number 2, 4, 6, 8, 10, 12, 14, 16, 18 and 20 are even numbers.

Stary! It is not possible to form pairs of objects everytime to decide if the number is odd or even

Stary! It is not possible to form pairs of objects everytime to decide if the number is odd or even

Here is a nice idea.

If the number 1, 3, 5, 7, or 9 are found in the unit place of the numbers,

then they are called odd numbers.

If the number 2, 4, 6, 8 or 0 are found in the unit place of the numbers,then they are called even numbers.

I’m sure you are can now easily identify odd & even number.

Ok! Then let us saw a few example.

Here are some numbers.

Can you identify which one are odd number and which one are even numbers?

Let’s start with number 21.

It has a district 1 in the unit place so 21 is an odd number.

Number 38 has 8 in the unit place so it is an even number.

In the number 43 the district in the unit place is 3,so 43 is an odd number.

the next number is 57. will it be odd or even number, Stary?

Yes since the district in the unit place is 7. 57 is an odd number.

Similarly we see that the number 64, 70, 96 and 58 are even numbers and they have 4, 0, 6 and 8 in their unit place.

Stary we are now left with the number 89 and 25 .

the number 89 and 25 are odd and they have 9 and 5 in their unit place.

Now let us saw the next example.

Stary fill in the missing odd numbers in this strip.

the odd number given are 33, 37, 41, 49 so which are missing odd numbers .

Yes they are 35, 39, 43, 45 and 47.

The next example is simple Stary.

we have to write 10 consecutive even number after 62.

Come on write fast.Yes, 64, 66, 68,70,72, 74, 76, 78, 80, 82

Stary remember we can easily find out whether a given number is odd or even by observing the district in each unit place

BÀI 9

 here are some stickers with numbers on them.

Pick any find stickers you like.

Oh, you have already chosen the stickers which you like.

Good Starry, look at the stickers!

All of them have even numbers on them, like that confused look Starry.

Uh, you seem to have forgotten about even numbers.

                                        

Okay, let us device.

If any of the digits 0, 2, 4, 6, 8 is in the units place of a number, then it is an even number.

Look at the units place of these numbers.

Each number has 0, 2, 4, 6, or 8 in the units place.

So these are even numbers.        

Now, if any of the digit 1, 3, 5, 7, 9 is in the units place of a number then it is odd numbers.

Look at the units place of these. Each number has either 1, 3, 5, 7, or 9 in the units place.

So these numbers are odd numbers. Starry, isn’t it interesting!

Now, let us do an activity. Circle the even numbers.

The even numbers are 356, 22, 600, 18, and 64.

Now, let us circle the odd numbers.

The odd numbers are 39, 617, 25, 183, 111.

Now, let us do something interesting. Let us make two three digit numbers using the given digits.

The even numbers made by using 5, 8, and 3 are 358 and 538.

The even numbers made using the digits 4, 1, 7 are 174 and 714.

The even numbers made by using the digits 9, 5, 0 are 950 and 590.

Now, let us make two three digit odd numbers using the even digits.

The odd numbers made by using 6, 4, 9 are 649 and 469.

The odd numbers made by using the digits 0, 3, 7 are 703 and 307.

The odd numbers made by using 5, 2, 6 are 265 and 625.

So, today we have learned about three odd and even numbers and how to make such numbers using the given digits.

Byeee, see you again!

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