Archive | Times Tables

How to See Why the Divisibility Trick for 3 Works

There’s a nifty trick for finding out if 3 divides evenly into a number. This little proof shows why the trick works.

Times Tables, Learning the Threes

Learning times tables can seem like drudgery. But here’s a fun, rhythmic game approach to learning the threes. Try it and see if you don’t have success.

Multiplication Trick #3 — Multiply by 25 FAST!

Here’s a great way to help students get two for the price of one. First, they make connections between multiplication and a topic very dear to their hearts: money. That’s because the trick is for multiplying by 25, and in using this trick, you use the fact that four quarters make a dollar. Secondly, students […]

Multiplication Trick #2 — Multiply by 15 FAST!

Here’s a great trick that helps you quickly multiply by 15. It’s handy for many real life situations, such as when you need to calculate a 15% tip at a restaurant. It involves nothing more than simple math. Try it, and then watch as your friends and family gaze in amazement.