High School

Shaha used a calculator to evaluate [tex]218 \div 31[/tex] and obtained the answer 70.3. Without doing the actual calculation, use estimation to determine whether Shaha's answer is reasonable. Then use a calculator to evaluate [tex]218 \div 31[/tex]. Is your estimated value close to the actual value?

Answer :

To determine if Shaha's answer of 70.3 is reasonable for the division 218 \div 31, we can use estimation.

Firstly, let's round the numbers to make the calculation easier:

  1. Round 218 to 220.
  2. Round 31 to 30.

Now, divide the rounded numbers:

[tex]\frac{220}{30} \approx 7.33[/tex]

The estimated answer is 7.33, which is significantly different from 70.3. This suggests that Shaha's answer is likely not reasonable.

Next, let's do the actual calculation using a calculator:

218 \div 31 \approx 7.0323

This value is indeed much closer to our estimate of 7.33, and not close to 70.3.

It seems there was a mistake in Shaha's calculation on the calculator, possibly due to a typo or an error in entering the numbers.

As a side note, calculating 218 + 31 does not relate directly to determining the reasonableness of the division operation 218 \div 31, but the addition would simply be:

218 + 31 = 249.

Other Questions