Practice Rounding in Math

Use these practice problems to test your method after reviewing the concept explanation and worked examples.

Quick Recap

Replacing a number with a nearby simpler approximation at a specified place value, using the digit to the right to decide.

Simplifying for easier calculation or communicationβ€”\$19.87 becomes 'about \$20'.

Showing a random 20 of 50 problems.

Example 1

medium
Use rounding to estimate 79Γ—4179 \times 41. Then compute the exact product.

Example 2

hard
Round 0.999990.99999 to the nearest hundredth.

Example 3

medium
Round 4,5674{,}567 to two significant figures.

Example 4

medium
Round 0.04560.0456 to the nearest thousandth.

Example 5

challenge
A statistician must round each of 0.5,1.5,2.5,3.50.5, 1.5, 2.5, 3.5 to the nearest whole number. Compare the totals using round-half-up vs round-half-to-even.

Example 6

easy
Round 8.9658.965 to the nearest hundredth. Then round βˆ’3.45-3.45 to the nearest tenth.

Example 7

easy
Round 4.054.05 to the nearest tenth (round half up).

Example 8

hard
What is the maximum possible value of a number that rounds to 5.75.7 (to the nearest tenth)?

Example 9

medium
Round Ο€β‰ˆ3.14159265…\pi \approx 3.14159265\ldots to 44 significant figures. Then round 0.00384720.0038472 to 33 significant figures.

Example 10

hard
Round 0.499990.49999 to the nearest whole number, then to the nearest tenth.

Example 11

easy
Round 295295 to the nearest ten.

Example 12

challenge
Three numbers each round to 1010 (nearest ten). What is the maximum possible value of their sum, using whole numbers?

Example 13

easy
Estimate 38+5138 + 51 by rounding each to the nearest ten.

Example 14

hard
A class of 3434 students must be split into groups of 66. Round up to find the minimum number of groups.

Example 15

medium
Estimate 487+312487 + 312 by rounding each to the nearest hundred, then compare to the exact answer.

Example 16

medium
Round 0.4990.499 to the nearest whole number.

Example 17

medium
Round 2.718282.71828 to (a) the nearest tenth, (b) the nearest thousandth.

Example 18

medium
Round 9,9999{,}999 to the nearest hundred.

Example 19

medium
Estimate 612Γ—19612 \times 19 by rounding.

Example 20

medium
Round 0.045670.04567 to (a) 22 decimal places, (b) 33 decimal places, (c) 33 significant figures.