Multiply by 8, using repeated addition

In this activity, we will learn about multiplying by 8.

 

To multiply by eight, we can use repeated addition.

 

Here is an octopus. One octopus has eight arms.

 

 

Let's think about what happens if we have 5 octopuses, each with 8 arms and we want to find the total number of arms!

 

 

 

We could count the arms one by one but this would take a while!

 

Instead, let's use repeated addition to show the total. 

5 groups of 8 looks like this as repeated addition

8 + 8 + 8 + 8 + 8 = 40

There are 40 arms in total!

 

Now let's try an example of multiplying by 8, using repeated addition. 

 

Example

Here are 4 octopuses. They each have 8 arms. How many arms in total?

 

 

Answer

In total, there are 8 + 8 + 8 + 8 = 32 arms.

What is 8 times 4?

8 × 4 = 32

4 × 8 = 32

 

Now that you understand repeated addition, let's try some more questions.