Ever wanted to impress everyone by solving complex multiplication problems in your head, without needing a pencil or paper? It's not magic; it's mental math—a superpower you can learn! This article is ...

The first line of the calculation is the same procedure as multiplying with a single digit number. In the second line we are multiplying by \(20\) (two tens). As we are multiplying by tens the unit's ...

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 ...