We’ve all seen those games where you try to guess how many jelly beans are in a jar. When it’s too hard to count ‘em up and too much time to calculate, it’s time to guesstimate the answer. I use this technique all the time to “ball park” my answer so I know if I’ve made a mistake with my final answer. This lesson is useful when you don’t need an exact answer, or if the numbers are way too long to remember. There’s even a free printable to help you out.