Final answer:
To estimate sums or differences, we round each number to its highest place value and then perform the addition or subtraction. For example, 933 + 576 can be estimated by rounding to 1000 + 600, giving an estimated sum of 1600.
Step-by-step explanation:
The student has asked to estimate each sum or difference by rounding each number to its highest place value. Here's how we can perform these estimations:
- a. For 933 + 576, we round 933 up to 1000 (since 9 is in the hundreds place) and 576 up to 600, so the estimated sum is 1000 + 600 = 1600.
- b. For 316 + 498 + 225, we round each number to the highest place value which results in 300 + 500 + 200, thus the estimated sum is 1000.
- c. To estimate 738 - 285, we round 738 to 700 and 285 to 300. The estimated difference is 700 - 300 = 400.
- d. Finally, for 1,387 + 2,635, we round 1,387 to 1,000 and 2,635 to 3,000, resulting in an estimated sum of 4,000.
Remember, when estimating by rounding to the highest place value, you look at the leftmost digit to determine how to round. Adding or subtracting the rounded figures provides an estimate of the original operation.