Truncating

When you begin estimating calculations, think of your mind as a Mighty Number Transformation Machine or MNTM for short. When you estimate, it can input any number, transform it, and output another number.

How does your mind do this? There are a few different techniques it can use. Today we will focus on the first way which is to shorten numbers to make them easier to work with. In math this is called truncating.

For example, when truncating the number 515 we remember how many groups of 100s there are. We truncate 515 to five.

Dogs like to think of truncating as biting off some digits. The idea behind biting off some digits is to get numbers with fewer digits that are easier to add, subtract, multiply, and divide. Of course even dogs, when they bite the number 45 and leave only a 4, have to remember that the 4 means 4 groups of 10.

So if you were trying to estimate what 432 + 812 = and wanted to use truncating, how would you do it?

You'd say 4 hundred + 8 hundred = 12 hundred = 1,200.

Truncating is a very fast way to estimate.