Question

Useing compatible numbers to estimate the following: would answer be 72 or 90
8.9 x 9.9 =

Answer 1

8.9 is close to 9
9.9 is close to 10

so you could estimate things by saying 9*10 = 90

Answer 2

turns out that 8.9*9.9 = 88.11, which is pretty close

Answer 3

Thank you , I did not know if I had to round the numbers.

Answer 4

yes with estimation you round to easier numbers to deal with