In this activity, we will round numbers to the nearest ten to estimate the answer to a multiplication.

Example

Estimate the answer by rounding the numbers to the nearest 10 before multiplying.

78 x 43

A

x

B

=

C

Answer

78 x 43

80

x

40

=

3200

Remember, to work out 80 x 40, we work out 8 x 4 x 10 x 10 = 32 x 100 = 3,200

Let's try some questions.