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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