To estimate the total weight of two boxes that weigh 9.4 pounds and 62.6 pounds using rounding and compatible numbers, you can round each weight to the nearest ten or hundred and then add them together. Let's round to the nearest ten for this example:
1. Round 9.4 pounds to the nearest ten, which is 10 pounds.
2. Round 62.6 pounds to the nearest ten, which is 60 pounds.
Now, add the rounded weights:
10 pounds + 60 pounds = 70 pounds
The estimated total weight using rounding is 70 pounds.
Now, let's compare this estimate to the actual total weight:
Actual total weight = 9.4 pounds + 62.6 pounds = 72 pounds
The actual total weight is 72 pounds.
The estimate using rounding (70 pounds) is closer to the actual total weight (72 pounds). Rounding to the nearest ten in this case gave a more accurate estimate because it was compatible with the given weights, making it easier to perform mental calculations.