To solve the problem, we need to estimate the sum and difference by rounding off the numbers to the nearest convenient value (usually to the nearest thousand or hundred, depending on the magnitude of the numbers). Let's go through each part step by step.
Estimate the Sum
1.
3,854 + 6,028
- Round 3,854 to the nearest thousand: 4,000
- Round 6,028 to the nearest thousand: 6,000
- Estimated sum: \( 4,000 + 6,000 = 10,000 \)
2.
8,322 + 1,103
- Round 8,322 to the nearest thousand: 8,000
- Round 1,103 to the nearest thousand: 1,000
- Estimated sum: \( 8,000 + 1,000 = 9,000 \)
3.
67,551 + 85,302
- Round 67,551 to the nearest thousand: 68,000
- Round 85,302 to the nearest thousand: 85,000
- Estimated sum: \( 68,000 + 85,000 = 153,000 \)
4.
10,364 + 59,493
- Round 10,364 to the nearest thousand: 10,000
- Round 59,493 to the nearest thousand: 59,000
- Estimated sum: \( 10,000 + 59,000 = 69,000 \)
5.
94,650 + 2,113
- Round 94,650 to the nearest thousand: 95,000
- Round 2,113 to the nearest thousand: 2,000
- Estimated sum: \( 95,000 + 2,000 = 97,000 \)
Estimate the Difference
1.
9,493 − 2,324
- Round 9,493 to the nearest thousand: 9,000
- Round 2,324 to the nearest thousand: 2,000
- Estimated difference: \( 9,000 - 2,000 = 7,000 \)
2.
5,036 − 1,945
- Round 5,036 to the nearest thousand: 5,000
- Round 1,945 to the nearest thousand: 2,000
- Estimated difference: \( 5,000 - 2,000 = 3,000 \)
3.
68,931 − 11,585
- Round 68,931 to the nearest thousand: 69,000
- Round 11,585 to the nearest thousand: 12,000
- Estimated difference: \( 69,000 - 12,000 = 57,000 \)
4.
74,832 − 15,002
- Round 74,832 to the nearest thousand: 75,000
- Round 15,002 to the nearest thousand: 15,000
- Estimated difference: \( 75,000 - 15,000 = 60,000 \)
5.
35,846 − 5,394
- Round 35,846 to the nearest thousand: 36,000
- Round 5,394 to the nearest thousand: 5,000
- Estimated difference: \( 36,000 - 5,000 = 31,000 \)
Final Answers
-
Estimated Sums:
- \( 3,854 + 6,028 \approx 10,000 \)
- \( 8,322 + 1,103 \approx 9,000 \)
- \( 67,551 + 85,302 \approx 153,000 \)
- \( 10,364 + 59,493 \approx 69,000 \)
- \( 94,650 + 2,113 \approx 97,000 \)
-
Estimated Differences:
- \( 9,493 - 2,324 \approx 7,000 \)
- \( 5,036 - 1,945 \approx 3,000 \)
- \( 68,931 - 11,585 \approx 57,000 \)
- \( 74,832 - 15,002 \approx 60,000 \)
- \( 35,846 - 5,394 \approx 31,000 \)
Boxed Final Answer:
\[
\boxed{
\begin{array}{rcl}
3,854 + 6,028 & \rightarrow & 4,000 + 6,000 = 10,000 \\
8,322 + 1,103 & \rightarrow & 8,000 + 1,000 = 9,000 \\
67,551 + 85,302 & \rightarrow & 68,000 + 85,000 = 153,000 \\
10,364 + 59,493 & \rightarrow & 10,000 + 59,000 = 69,000 \\
94,650 + 2,113 & \rightarrow & 95,000 + 2,000 = 97,000 \\
\hline
9,493 - 2,324 & \rightarrow & 9,000 - 2,000 = 7,000 \\
5,036 - 1,945 & \rightarrow & 5,000 - 2,000 = 3,000 \\
68,931 - 11,585 & \rightarrow & 69,000 - 12,000 = 57,000 \\
74,832 - 15,002 & \rightarrow & 75,000 - 15,000 = 60,000 \\
35,846 - 5,394 & \rightarrow & 36,000 - 5,000 = 31,000 \\
\end{array}
}
\]
Parent Tip: Review the logic above to help your child master the concept of estimation 4th grade math worksheet.
