Meghan was trying to estimate 997,286 + 129,092. Her estimated sum was 300,000. What mistake did she make? What is the correct estimated sum?

Question

What mistake did she make?  What is the correct estimated sum?

Answer 1

The mistake Becky most likely made was not realizing the commas and decimal points to see the actual magnitude of the numbers. The first is nearly a 1,000,000 while the second is nearly 130 thousand. So the actual estimate, rounded up, is approximately 1,130,000.

 

This makes sense because when we do the actual calculation of 997,286.00 + 129,092.00 = 1,126,378.00 which is sufficiently close to the estimate of 1,130,000.