Rounding to the Nearest 10 and 100
Skill: Rounding whole numbers to the nearest ten or hundred
Download PDF worksheetAnswer key (PDF)
Free for personal and classroom use. Print at 100% / "Actual size" on US Letter paper.
About this worksheet
Rounding helps students estimate, check whether answers make sense, and do quick mental math. This third-grade worksheet has two parts. In Part A, students round ten numbers to the nearest ten. In Part B, they round ten numbers to the nearest hundred. The numbers range from two-digit to three-digit, and each part includes a number that sits exactly halfway, such as 45 or 650, so students can practice the rounding convention for that case.
The idea behind rounding is closeness. To round 347 to the nearest ten, ask whether it is closer to 340 or 350. Because 347 is only 3 away from 350, it rounds to 350. To round it to the nearest hundred, compare 300 and 400; it is closer to 300. When a number is exactly in the middle, the usual rule is to round up, so 45 rounds to 50.
How to use it: before using a rule, let students sketch a quick number line with the two possible answers at each end and the halfway point marked in the middle. Placing the number on the line shows which end is closer. Once that makes sense, introduce the shortcut: look at the digit just to the right of the place you are rounding to.
The answer key gives every rounded number. This worksheet supports Common Core standard 3.NBT.A.1 (use place value understanding to round whole numbers to the nearest 10 or 100).
Count and Trace Numbers 1-10
Addition Within 10
Subtraction Within 10