Round the numbers so that there is only one non-zero digit, and estimate the answer. Then perform the indicated
operation to find the exact answer.
-544.4 - 5.039
A)estimate: 495; exact: 539.461
B)estimate: 495; exact: 539.361
C)estimate: 595; exact: 549.361
D)estimate: 495; exact: 539.371

Question

Quizplus · Accepted Answer

Rounding 544.4 to the nearest hundred gives 500. Rounding 5.039 to the nearest hundredth gives 5.04.

Hence, the estimated answer is 500-5=495.

Subtracting the exact values gives:

544.4 - 5.039 = 539.361

Therefore, the best choice is B, which corresponds to an estimated value of 495 and an exact value of 539.361. If we round the numbers to the nearest hundredth, we get 544.40 - 5.04 = 539.36. This is closest to choice B, which has an exact answer of 539.361.

Round the Numbers So That There Is Only One Non-Zero