Bài 12: Multiplication using a number line

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Hey Starry, today we are going to have a lot of fun learning Math.

See, I have brought some strips on which a number line has be drawn.

Do you know what is a number line?

Yes, in a number line a horizontal line is drawn with arrows on both sites.

Starting from zero, numbers are written on  it at equal distances.

The distance between 1 number to the next is generally considered   as 1 unit.

Here, let me stick the first strip.

Now Starry, we are going to solve some multiplication example using this strip.

Consider the example 2 multiply by 5.

Starry, now starting from 0 ,you have to take five jumps of twos to the right.

Yes, now jumps from 0 to 2, 2 to 4, 4 to 6, 6 to 8, and 8 to 10.

We reach the number 10. So Starry, 2 multiply by 5 is equal to 10.

Let us consider the next example. 
Multiply 2 8 times.

Now Starry, will you jump?

Yes, starting from 0, move to 2 then 4 6 8 10 12 14 16.

Have you jumped 8 times?

Okay, we have reached the number 16.

So 2 multiply 8 times is equal to 16.

Are you enjoy the game Starry?

Ok, let us now stick the next strip.

Starry, you have to jumped forward by counting numbers in stages of three.

                       

Consider the example 3 into 3.

So how many times will you jump?

Yes, you have to jump 3 times to the right.

So starting from 0 you jump to 3 then 6 and then 9.

So 3 into 3 is equal to 9.

The next example is 3 taking 5 times.

So what will you do Starry?

Yes, take 5 jumps of threes to the right.

So from 0 you jump to 3 then 6 9 12 and 15.

We reach the number 15. 
So 3 into 5 equal 15.

What happened, Starry?
 Oh, you are tired jumping!

Um, I have an idea, let us use a pencil and solve multiplication example using a number line.

Let us consider the example 4 into 6.

Starting from 0, we shall move the pencil to the right by counting forward in stages of 4.

How many such numbers should we select?

Yes, 6, reach the number 24.
So 4 into 6 is equal to 24.

Let solve one more example.

How much is 6 multiply by 2 Starry?

We shall start from 0, take to jump of sixes to the right.

What is the answer Starry?

Yes, 6 multiply by 2 is 12.

Here the last one Starry.

Solve 5 multiply by 4.

Yes, we shall go from 0 to the number 5 then move to 10, 15 and in the end we reach the number 20.

So 5 multiply by 4 is equal to 20.

Remember, this method of solving multiplication is easy only if the numbers are small.

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