Let's solve each problem step by step from the worksheet titled
"Estimating Decimal Sums and Differences Problems – Independent Practice Worksheet".
We are asked to estimate sums by rounding each decimal to a specified place value (tenths, hundredths, etc.) before adding.
---
Problem 1: Estimate the sum of 6.14 and 4.57 by rounding to the nearest tenth.
- Round
6.14 to the nearest tenth:
Look at the hundredths digit (4), which is less than 5 → round down.
So,
6.14 ≈ 6.1
- Round
4.57 to the nearest tenth:
Hundredths digit is 7 ≥ 5 → round up.
So,
4.57 ≈ 4.6
- Now add:
6.1 + 4.6 = 10.7
✔ Answer: 10.7
---
Problem 2: Estimate the sum of 0.61 and 0.76 by rounding to the nearest tenth.
-
0.61 → hundredths digit is 1 < 5 → round down →
0.6
-
0.76 → hundredths digit is 6 ≥ 5 → round up →
0.8
- Add:
0.6 + 0.8 = 1.4
✔ Answer: 1.4
---
Problem 3: Estimate the sum of 1.31 and 9.17 by rounding to the nearest hundredth.
Wait — this says "rounding to the nearest hundredth", but both numbers are already to the hundredth place.
-
1.31 → already at hundredths → stays
1.31
-
9.17 → already at hundredths → stays
9.17
Add:
1.31 + 9.17 = 10.48
But since we're estimating by rounding to the nearest hundredth, and they're already in that form, we just add them as-is.
✔ Answer: 10.48
> Note: This seems odd because estimating usually implies rounding *before* adding. But if it says "round to nearest hundredth," and the numbers are already precise to hundredths, then no change is needed.
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Problem 4: Estimate the sum of 0.87 and 0.11 by rounding to the nearest tenth.
-
0.87 → hundredths digit is 7 ≥ 5 → round up →
0.9
-
0.11 → hundredths digit is 1 < 5 → round down →
0.1
Add:
0.9 + 0.1 = 1.0
✔ Answer: 1.0
---
Problem 5: Estimate the sum of 4.51 and 7.91 by rounding to the nearest hundredth.
Again, both numbers are already to the hundredth place.
-
4.51 → stays
4.51
-
7.91 → stays
7.91
Add:
4.51 + 7.91 = 12.42
✔ Answer: 12.42
---
Problem 6: Estimate the sum of 0.38 and 0.34 by rounding to the nearest tenth.
-
0.38 → hundredths digit 8 ≥ 5 → round up →
0.4
-
0.34 → hundredths digit 4 < 5 → round down →
0.3
Add:
0.4 + 0.3 = 0.7
✔ Answer: 0.7
---
Problem 7: Estimate the sum of 9.19 and 9.97 by rounding to the nearest hundredth.
Both numbers are already at hundredths:
-
9.19 → stays
9.19
-
9.97 → stays
9.97
Add:
9.19 + 9.97 = 19.16
✔ Answer: 19.16
---
Problem 8: Estimate the sum of 0.19 and 0.24 by rounding to the nearest tenth.
-
0.19 → hundredths digit 9 ≥ 5 → round up →
0.2
-
0.24 → hundredths digit 4 < 5 → round down →
0.2
Add:
0.2 + 0.2 = 0.4
✔ Answer: 0.4
---
Problem 9: Estimate the sum of 8.31 and 7.48 by rounding to the nearest hundredth.
Already at hundredths:
-
8.31 → stays
8.31
-
7.48 → stays
7.48
Add:
8.31 + 7.48 = 15.79
✔ Answer: 15.79
---
Problem 10: Estimate the sum of 0.25 and 0.34 by rounding to the nearest tenth.
-
0.25 → hundredths digit 5 → round up →
0.3
-
0.34 → hundredths digit 4 < 5 → round down →
0.3
Add:
0.3 + 0.3 = 0.6
✔ Answer: 0.6
---
✔ Final Answers:
1.
10.7
2.
1.4
3.
10.48
4.
1.0
5.
12.42
6.
0.7
7.
19.16
8.
0.4
9.
15.79
10.
0.6
---
🔍 Explanation Summary:
-
Rounding to the nearest tenth: Look at the
hundredths digit:
- If it's
5 or more, round up.
- If it's
less than 5, round down.
-
Rounding to the nearest hundredth: Look at the
thousandths digit (but since all numbers here only go to hundredths, no rounding is needed).
- After rounding,
add the rounded values to estimate the sum.
This method gives a quick approximation, useful for checking reasonableness of exact answers.
Let me know if you'd like a printable version or want to check any specific problem!
Parent Tip: Review the logic above to help your child master the concept of estimating sums and differences worksheets.
