Lesson

We've seen how multiplying by 2 helps us multiply by 4, and then by 8. Let's try this problem to help us remember.

Find 6 \times 8.

Worked Solution

Idea summary

We can use any of the following to work out multiplications:

repeated addition

arrays to show equal sized groups

patterns, such as doubling and skip-counting

multiplication tables

What if we could use things we already know to solve multiplication or division? We can. Let's see how.

If 2 \times 8 =16, what is 20 \times 8?

Worked Solution

Idea summary

For every multiplication problem we know, there's another one we also know. If we know our 3 times tables, including 3 \times 7 = 21, then we know that 7 \times 3 = 21.