To estimate each sum or difference, you round the numbers to the nearest place value (typically the highest place value) and then perform the operation. Let's go through each problem on the worksheet.

1. 2,513 + 7,428

   • Rounded: 2,500 + 7,400 = 9,900

2. 4,125 + 3,036

   • Rounded: 4,000 + 3,000 = 7,000

3. 912 + 688

   • Rounded: 900 + 700 = 1,600

4. 14,032 - 7,841

   • Rounded: 14,000 - 8,000 = 6,000

5. 6,927 - 4,231

   • Rounded: 7,000 - 4,000 = 3,000

6. 391,974 + 511,804

   • Rounded: 392,000 + 512,000 = 904,000

7. 8,935 + 1,259

   • Rounded: 9,000 + 1,300 = 10,300

8. 812,910 - 700,685

   • Rounded: 813,000 - 701,000 = 112,000

These estimations simplify the calculations and give you a close approximation of the actual sum or difference.

Would you like more details on any of these? Or perhaps a deeper dive into the concept of rounding and estimation?

Here are five related questions to expand your understanding:

1. How do you determine which place value to round to when estimating?
2. What are some common mistakes people make when estimating sums and differences?
3. How does the accuracy of your estimation change if you round to different place values?
4. Can you think of a situation where a more accurate estimation would be necessary?
5. How would rounding differently affect the outcome of an estimation involving large numbers?

Tip: Always double-check which place value you are rounding to; rounding to the highest place value generally gives the best estimate for large sums and differences.