Answer
estimate - 79
exact - 79$\frac{7}{16}$
Work Step by Step
215$\frac{7}{16}$ - 136
Estimate : 215$\frac{7}{16}$ round to 215
136 round to 136
So subtract 215 – 136 = 79 is the estimate answer
Exact : 215$\frac{7}{16}$ - 136
It is not possible to subtract $\frac{7}{16}$ without regrouping the whole number 136 first
136 = 135 + 1 = 135 + $\frac{16}{16}$ = 135$\frac{16}{16}$
215$\frac{7}{16}$ = 214 +1 + $\frac{7}{16}$ = 214 + $\frac{16}{16}$ + $\frac{7}{16}$
= 214 + $\frac{23}{16}$ = 214$\frac{23}{16}$
Subtract : 214$\frac{23}{16}$ - 135$\frac{16}{16}$
Subtraction of the whole number is 79 and Subtraction of the fraction is $\frac{7}{16}$
= 79$\frac{7}{16}$
The estimate was 79, so the exact answer of 79$\frac{7}{16}$ is reasonable
