How to estimate sums and differences

Hello from MrBillDoesMath!

example estimates: 1.3, 1.4

Discussion:

According to the question author  we need to estimate sum of

9/10 + 7/16

The question is how good an estimate is needed! For example, here's a quick, but hardly accurate, estimate:

9/10 + 7/16 is approx  9/10 + 8/16 = 9/10 + 1/2 = 9/10 + 5/10 = 14/10 = 1.4

Here's a more accurate estimate:

9/10 + 7/16 =  (9*8)/80 +     (7*5)/ 80 =

                 (72 + 35)/80 =

                 107/80  = which is about 1.3

Thank you,

MrB

a

step-by-step explanation:

the answer is a