Rounding Decimals Worksheets

Sample problems

1. Round to the nearest tenth: 2.47, 0.83, 5.05.
2. Round to the nearest hundredth: 0.416, 3.798, 12.005.
3. Round to the nearest whole number: 8.5, 0.49, 19.62.
4. Round 0.749 to the nearest tenth. Then round 0.741 to the nearest tenth. Should they be the same?

Common mistakes to watch for

• Answered 0.8 and 6.29 — both rounded in stages (0.749 to 0.75 to 0.8; 6.284 to 6.29 by looking at the 4 after rounding the thousandths). Writing the candidates and midpoint down first is what makes this impossible.
• Answered 4, 3.6, 3.55 — the tenth arrived at from the 3.55 in the third answer. The three parts are deliberately printed together, and using one answer to produce another is precisely the error.
• Said Kai “rounded twice, and you should only round once”. That is the rule and not the reason; what makes it stick is seeing that staging hands a decision to a digit which the question does not consult, and the 3.541 comparison is the cleanest way to show it.

The answer key explains each one, so you can tell what a wrong answer means.