A focused Grade 5 learning session for Rounding Decimals using visual models, worked examples, strategy guidance, and a short mastery check.
Student goal: I can round decimals to the requested place.
Rounding Decimals is the Grade 5 skill of students use place value understanding to round decimals to any place. They apply rounding to estimate answers and check the reasonableness of results in problem-solving contexts.
Strong understanding comes from naming what the numbers, shapes, units, or data values represent, then showing the idea with a model or clear steps before solving.
The key to this topic is understanding the structure behind the work, not just following a rule. Students should be able to talk through what is happening, point to a model, and explain why the answer makes sense.
Question: Round 23.45 to the nearest whole number.
| Tens | Ones | Tenths | Hundredths |
|---|---|---|---|
| 2 | 3 | 4 | 5 |
How the model helps: The tenths place is 4. Since 4 is less than 5, round down. 23.45 rounded to the nearest whole number is 23.
Question: Maria measures 8.762 meters of ribbon. If she rounds to the nearest tenth for her project, how much does she use?
Answer: 8.8 m
Question: What is the place-value chart showing for 3.456? When \(3.456\) is rounded to the nearest hundredth, which digit changes because the thousandths digit is 6?
| Ones | Tenths | Hundredths | Thousandths |
|---|---|---|---|
| 3 | 4 | 5 | 6 |
Answer: The hundredths digit, 5
Question: A store item costs $12.456. Round to the nearest cent (hundredth of a dollar).
Answer: $12.46
Why it works: Rounding \(12.456 to the nearest cent (hundredth): the thousandths digit is 6. Since \)6 \geq 5\(, round the hundredths digit up: 5 becomes 6, giving \)12.46.
Rounding Decimals gets easier when students read the model, track what each number means, and explain why the answer fits the situation.
Name the place value first, then compute or compare with aligned digits.
Use scratch paper. The explanation matters more than simply seeing whether the choice is correct.
% Test Text What is 47.863 rounded to the nearest tenth?
Answer C: 47.9
% Explanation Text The tenths place in 47.863 is 8. The hundredths place is 6. Since 6 is greater than or equal to 5, we round the tenths digit up from 8 to 9. Therefore, 47.863 rounded to the nearest tenth is 47.9.
Round 23.45 to the nearest whole number.
Answer A: 23
The tenths place is 4. Since 4 is less than 5, round down. 23.45 rounded to the nearest whole number is 23.
What is 5.678 rounded to the nearest hundredth?
Answer B: 5.68
The hundredths place is 7. The thousandths place is 8. Since 8 \(\geq\) 5, round up from 7 to 8. So 5.678 rounds to 5.68.
Round 12.542 to the nearest tenth.
Answer D: 12.5
The tenths place is 5. The hundredths place is 4. Since 4 < 5, keep 5. So 12.542 rounds to 12.5.
A number line shows the position of 3.47 between 3 and 4. What is 3.47 rounded to the nearest whole number?
Answer D: 3
3.47 is between 3 and 4, but closer to 3 because the tenths digit 4 is less than 5. It rounds down to 3.
Round 9.951 to the nearest hundredth.
Answer A: 9.95
The hundredths place is 5. The thousandths place is 1. Since 1 < 5, keep the hundredths digit the same. So 9.951 rounds to 9.95.
Maria measures 8.762 meters of ribbon. If she rounds to the nearest tenth for her project, how much does she use?
Answer C: 8.8 m
The tenths place is 7, hundredths is 6. Since 6 \(\geq\) 5, round up: 7 becomes 8. Maria uses 8.8 meters.
What is the place-value chart showing for 3.456? When \(3.456\) is rounded to the nearest hundredth, which digit changes because the thousandths digit is 6?
Answer D: The hundredths digit, 5
The thousandths digit 6 tells whether to round up. Since 6 \(\geq\) 5, the hundredths digit changes from 5 to 6.
Round 34.196 to the nearest whole number.
Answer A: 34
The tenths digit is 1. Since 1 < 5, round down. 34.196 rounded to the nearest whole number is 34.
A package weighs 6.846 kg. Round to the nearest hundredth for shipping records.
Answer C: 6.85 kg
Rounding 6.846 to the nearest hundredth: the thousandths digit is 6. Since \(6 \geq 5\), round the hundredths digit up: 4 becomes 5, giving 6.85 kg.
Which number would round to 7.2 when rounding to the nearest tenth?
Answer B: 7.19
7.19 has a tenths digit of 1 and hundredths digit of 9. Since 9 \(\geq\) 5, round the tenths up from 1 to 2, giving 7.2.
