This article reveals a simple and effective shortcut for multiplying numbers that end in 5. Perfect for students, it breaks down the trick for both single-digit and double-digit numbers ending in 5, ...

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 ...

Methods similar to this go back thousands of years, at least to the ancient Sumerians and Egyptians. Around 1956, the famous Soviet mathematician Andrey Kolmogorov conjectured that this is the best ...

Methods similar to this go back thousands of years, at least to the ancient Sumerians and Egyptians. But is this really the best way to multiply two big numbers together? Around 1956, the famous ...

Most people know just one way to multiply two large numbers by hand. Typically, they learned it in elementary school. They’re often surprised to find that there are a variety of ways to do ...