Multiplication of two numbers is easy, right? At primary school we learn how to do long multiplication like this: Methods similar to this go back thousands of years, at least to the ancient Sumerians ...

Watch the video to learn about adding and subtracting with negative numbers on a number line and by using number discs. Adding and subtracting with negative numbers. Let's talk about two ways to help ...

Multiplying 2 x 2 is easy. But multiplying two numbers with more than a billion digits each — that takes some serious computation. The multiplication technique taught in grade school may be simple, ...