Answer:
Step-by-step explanation:
Part A:
Mark did not round to the nearest hundreds, he rounded to the nearest tens.
Option A (Incorrect):
271 and 582 are normally not rounded down, unless we are using limits coming from the left and a unique equation.
Option B (Incorrect):
271 as the same problem as option A, but 582 rounding to 600 is correct. It doesn't make sense to round both numbers differently, unless stated.
Option C (Incorrect):
271 rounding to 300 is correct, but 582 is not normally rounded down to 500 unless we are using limits coming from the left and a unique equation. Unless stated, don't round both numbers differently.
Option D (Correct):
271 rounded to 300 and 582 rounded to 600 looks correct for rounding to the hundreds.
Part B:
There are two ways to solve this question:
One way:
271 + 582 = 853
Round 853 to the nearest hundred for 900
(Note: Round 853 to the nearest tens for 850.)
Second way:
271 + 582
Round Numbers:
300 + 600
= 900