Lesson

Multiplication looks at equally sized groups. Doubling means multiplying equally sized groups by 2. Can you solve this problem?

Find the value of 2\times8.

Worked Solution

Idea summary

Multiplying by two is the same as doubling and can be thought of as the total of two equally sized groups.

4 groups is twice (two times) as many as 2 groups. Let's look at how to multiply numbers by 4 using the **Double, Double strategy**.

Find the product of 4\times 8.

Worked Solution

Idea summary

When multiplying by 2 and 4:

- Double means "multiply by 2."
- To multiply a number by 4, you can use the Double, Double strategy. That means, double the number, then double the answer.

uses mental and informal written strategies for multiplication and division