Question

Write how you would estimate the product of 347 and 42

Answer 1

1400 (see my explanation below)

Explanation:

This depends on whether you are being taught to round to the nearest 100 or nearest 10.

The closest estimate would be rounding to 10's.

350 x 40

Solve quickly in your head by doubling 350 (700)

Double it again (1400)

And then add a zero.

14,000

Why? Because you are breaking down the 40 in 2 x 2 x 10

Doubling twice takes care of the 2 x 2 and adding the zero takes care of the 10.

Answer 2

300 times 40

50 times 40

Add the answers together

Explanation:

For this I simplified 347 to 350 and split it to 300 and 50

I also estimated 42 to 40

Instead of doing 350 times 40 it’s easier to do (300 x 40) + (50 x 40)

I hope this helps