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 ...

19 is only 1 away from 20, so you prefer to start by multiplying 20 times 5, which equals 100. Then we need to take away a squadron of 5, because there are actually only 19 squadrons, not 20. 100 take ...

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 ...

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 ...

After duplex numbers, let us learn multiplication by triplex numbers. As the name suggests, numbers like 111, 222, 333 are triplex numbers. The method is similar to that of multiplication by duplex ...

The method that we learn in school is a long multiplication method. But this method is very time consuming. SO let’s learn a much faster way to multiply a 2-digit number by 11. Step 1 - Write 3 and 6 ...