Printable primary math worksheet for math grades 1 to 6 based on ... - Free Printable

Problem Overview:

The task involves rounding numbers to the nearest ten thousand and then estimating their sums. The worksheet provides pairs of numbers, and we need to:

1. Round each number to the nearest ten thousand.
2. Add the rounded numbers.
3. Write down the estimated sum.

Step-by-Step Solution:

#### Row 1:
- Numbers: 11,455 and 19,504
- Round 11,455 to the nearest ten thousand: 10,000
- Round 19,504 to the nearest ten thousand: 20,000
- Estimated Sum: \( 10,000 + 20,000 = 30,000 \)

- Numbers: 15,665 and 6,707
- Round 15,665 to the nearest ten thousand: 20,000
- Round 6,707 to the nearest ten thousand: 10,000
- Estimated Sum: \( 20,000 + 10,000 = 30,000 \)

#### Row 2:
- Numbers: 15,250 and 24,514
- Round 15,250 to the nearest ten thousand: 20,000
- Round 24,514 to the nearest ten thousand: 20,000
- Estimated Sum: \( 20,000 + 20,000 = 40,000 \)

- Numbers: 56,360 and 12,210
- Round 56,360 to the nearest ten thousand: 60,000
- Round 12,210 to the nearest ten thousand: 10,000
- Estimated Sum: \( 60,000 + 10,000 = 70,000 \)

- Numbers: 11,617 and 6,465
- Round 11,617 to the nearest ten thousand: 10,000
- Round 6,465 to the nearest ten thousand: 10,000
- Estimated Sum: \( 10,000 + 10,000 = 20,000 \)

#### Row 3:
- Numbers: 21,487 and 38,599
- Round 21,487 to the nearest ten thousand: 20,000
- Round 38,599 to the nearest ten thousand: 40,000
- Estimated Sum: \( 20,000 + 40,000 = 60,000 \)

- Numbers: 18,199 and 60,539
- Round 18,199 to the nearest ten thousand: 20,000
- Round 60,539 to the nearest ten thousand: 60,000
- Estimated Sum: \( 20,000 + 60,000 = 80,000 \)

- Numbers: 10,585 and 12,499
- Round 10,585 to the nearest ten thousand: 10,000
- Round 12,499 to the nearest ten thousand: 10,000
- Estimated Sum: \( 10,000 + 10,000 = 20,000 \)

#### Row 4:
- Numbers: 32,630 and 40,751
- Round 32,630 to the nearest ten thousand: 30,000
- Round 40,751 to the nearest ten thousand: 40,000
- Estimated Sum: \( 30,000 + 40,000 = 70,000 \)

- Numbers: 15,198 and 13,583
- Round 15,198 to the nearest ten thousand: 20,000
- Round 13,583 to the nearest ten thousand: 10,000
- Estimated Sum: \( 20,000 + 10,000 = 30,000 \)

- Numbers: 20,336 and 61,521
- Round 20,336 to the nearest ten thousand: 20,000
- Round 61,521 to the nearest ten thousand: 60,000
- Estimated Sum: \( 20,000 + 60,000 = 80,000 \)

#### Row 5:
- Numbers: 16,551 and 3,456
- Round 16,551 to the nearest ten thousand: 20,000
- Round 3,456 to the nearest ten thousand: 0
- Estimated Sum: \( 20,000 + 0 = 20,000 \)

- Numbers: 25,430 and 50,980
- Round 25,430 to the nearest ten thousand: 30,000
- Round 50,980 to the nearest ten thousand: 50,000
- Estimated Sum: \( 30,000 + 50,000 = 80,000 \)

- Numbers: 23,454 and 21,950
- Round 23,454 to the nearest ten thousand: 20,000
- Round 21,950 to the nearest ten thousand: 20,000
- Estimated Sum: \( 20,000 + 20,000 = 40,000 \)

#### Row 6:
- Numbers: 5,298 and 7,984
- Round 5,298 to the nearest ten thousand: 0
- Round 7,984 to the nearest ten thousand: 10,000
- Estimated Sum: \( 0 + 10,000 = 10,000 \)

- Numbers: 43,379 and 31,366
- Round 43,379 to the nearest ten thousand: 40,000
- Round 31,366 to the nearest ten thousand: 30,000
- Estimated Sum: \( 40,000 + 30,000 = 70,000 \)

- Numbers: 19,830 and 15,663
- Round 19,830 to the nearest ten thousand: 20,000
- Round 15,663 to the nearest ten thousand: 20,000
- Estimated Sum: \( 20,000 + 20,000 = 40,000 \)

#### Row 7:
- Numbers: 21,750 and 42,650
- Round 21,750 to the nearest ten thousand: 20,000
- Round 42,650 to the nearest ten thousand: 40,000
- Estimated Sum: \( 20,000 + 40,000 = 60,000 \)

- Numbers: 24,572 and 44,817
- Round 24,572 to the nearest ten thousand: 20,000
- Round 44,817 to the nearest ten thousand: 40,000
- Estimated Sum: \( 20,000 + 40,000 = 60,000 \)

- Numbers: 16,550 and 13,462
- Round 16,550 to the nearest ten thousand: 20,000
- Round 13,462 to the nearest ten thousand: 10,000
- Estimated Sum: \( 20,000 + 10,000 = 30,000 \)

Final Answer:

\[
\boxed{
\begin{array}{ccc}
30,000 & 30,000 & \\
40,000 & 70,000 & 20,000 \\
60,000 & 80,000 & 20,000 \\
70,000 & 30,000 & 80,000 \\
20,000 & 80,000 & 40,000 \\
10,000 & 70,000 & 40,000 \\
60,000 & 60,000 & 30,000 \\
\end{array}
}
\]