Question

To estimate the product of 21 x 78, what is the best way to round the factors? (2 points)

20 x 80
30 x 70
20 x 70
30 x 80

Answer 1

20x80

Explanation:

21 is closest to 20 and is rounded down, 80 is closest to 78 and rounded up so the closest and most logical estimate is a: 20x80.

Answer 2

I would say 20x80. These are the closest to 21 and 78