It's possible to solve some multiplication problems in your head. But sometimes it can help to use other methods instead. These include using visual aids, such as an array or place counters, or by ...

First we need to know what a duplex number is. Numbers like 11, 22, 33, 44 etc, with repeated digits, are called duplex numbers. We already know how to multiply by 11. Here we are going to learn a ...

It's possible to solve some multiplication problems in your head. But sometimes it can help to use other methods instead. These include using visual aids, such as an array or place counters, or by ...