Answer
estimate - 18
exact - 18$\frac{1}{3}$
Work Step by Step
34 - 15$\frac{2}{3}$
Estimate : 34 round to 34
15$\frac{2}{3}$ round to 16
So subtract 34 – 16 = 18 is the estimate answer
Exact : 34 - 15$\frac{2}{3}$
It is not possible to subtract $\frac{2}{3}$ without regrouping the whole number 34 first
34 = 33 + 1 = 33 + $\frac{3}{3}$ = 33$\frac{3}{3}$
Subtract : 33$\frac{3}{3}$ - 15$\frac{2}{3}$
Subtraction of the whole number is 18 and Subtraction of the fraction is $\frac{1}{3}$
= 18$\frac{1}{3}$
The estimate was 18, so the exact answer of 18$\frac{1}{3}$ is reasonable
