Dear Estimators,

Math is like horseshoes–most of the time, close enough is good enough. Usually, an estimate will give us the information we need. Sometimes, however, we  have to be precise. Good mathematicians have to know how to do both. More importantly, good mathematicians have to know when estimates are appropriate and when it’s time to calculate precisely. As always, math thinking is about creating a method for solving a problem, not just doing the arithmetic.

Today, we’ll make magnitude estimates for products. The orders of magnitude are the powers of ten–1, 10, 100, 1000, 10,000, etc. By estimating the magnitude of the product, we’ll not only be able to check our calculations, but we’ll learn about the wonders of our number system. That’s really what it’s all about.

Sincerely,

Mr. H