BÀI 14: DECIMALS: SỐ THẬP PHÂN

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https://www.youtube.com/watch?v=e1bWoNpxsKE

Welcome to decimals .

We 're used to seeing numbers like this.

 But  what about this.

This  dot here shows us that this number is not 24.

 This  is our whole number or our unit.

 We  have two units .

This  is called a decimal point .

And  this is how many tenths we have.

 Tenths  are a part of a whole number .

Numbers  after the decimal are similar to a fraction

They  represent part of a number.

 2.4 is in between 2 & 3 .

We  can see this more accurately when we add in the tenths.

In between every whole number ,there are ten tenths.

If  we put an arrow showing us where two-point-four goes.

This  is where it would be pointing it is 4/10 more than to.

Let  me show you how this looks using pizza .

This  is one pizza.

Here  we have two pizzas .

Here  is where our decimal point would go if we knew that, we had more than two pizzas and less than three pizzas.

This  is what two point four pizzas look like see.

We  have two whole pizzas and only part of the next pizza.

Let 's check that 12.4
See,We  have four slices of a pizza that was cut into ten pieces. 

Someone  must have eaten the other six slices.

So  we only have two point four pizzas left.

In  activity one, you will have to color in the amount you have using pictures.

Two  point four colored in looks like this.

Another  way to show how many of something we have is using a place value table.

We  have two units and so we write two in the unit's column .

The decimal goes in the decimal column.

And  I wonder if you can guess what goes in the tenths column.

That 's right it's a four because we have four tenths .

After  the decimal the further away from the point the smaller than number .

In  activity one, you learn about tenths and hundredths .

In this activity, you will have to fill in the place value table and color in one of the grids .

This  is how 1.92 looks in a place value table .

We  have it are one unit or whole our decimal in our decimals column.

We  have nine ten and two hundredths .

This  is a blank coloring grid and when we've colored it in 1.9 - looks like this.

Use  your imagination to think about how much pizza that is.

We  color in one unit because we have one of them .

We color in nine tenths because we have nine of them.

And  we color in two hundredths because we have two of them.

 So  we fill in the table and we color in the coloring grid.

When  you are done for each number ,you should have a table that's filled in and a colored grid.

 It  is now time to start activity one .

Make  sure you watch this video again if you're still unsure about

anything.

 If  you have any questions, make sure you either write them down for me to answer for you next time or ask your teacher for help.

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