📊🤔 Explore A - Lesson 3.4 Multiplication With Number Lines

Part 1

How do you skip count by 3's?

3, 6, 9, 12, 15, 18, 21, 24

How would you show this on a number line?

Each jump is of 3.  This is skip counting by 3.

Watch the video: Multiplication on a Number Line Links to an external site.

Part 2

$4\times5$

This means 4 groups of 5.  

On a number line, this is 4 jumps of 5.

You try it on your number line.

$4\times5$

4 jumps of 5 lands at 20.  So $4\times5$ equals 20.

Or  $4\times5=20$.

Part 3

$2\times7$

This is 2 jumps of 7.

Try this on your number line.

Part 3

Look at your multiplication chart.  (PDF at the beginning of section 3.4.)

How could you find the answer to a multiplication expression using the chart?

Let's look at $4\times5$.

We need 4 jumps of 5.

Look at row 5 on your chart.  What do you notice?

Do you see the end of each jump?  0, 5, 10, 15, 20.

Where is 20?  It is in the column marked "4".