Question

Which of the following is not an appropriate estimate for the sum of $32$ and $45$ when rounded to the nearest tens.

• A. $70$
• B. $85$
• C. $95$
• D. $80$

Answer 1

The correct option is C $95$

We need to find the appropriate estimate for the sum of 32 and 45, and select the incorrect option.
Let us find the sum using all possible combinations of different estimations.

Say:
$\bullet$ For ease of calculation, $32$ can be estimated to $30,35,$ or $40$
$\bullet$ Similarly, $45$ can be estimated to $40$ or $50$. For calculations, we can also use $45$ without estimation.
$\bullet$ Let us write down all the estimations as shown below :-

$\bullet$ Hence, as per the given options $70,80,$ and $85$ are the estimated sum for $32$ and $45$.
$\bullet$ Option D is correct.