Years ago, no math education was complete without understanding how to compute a square root. Today, you are probably just reaching for a calculator, or if you are writing a program, you’ll probably just guess and iterate. [MindYourDecisions] was curious how people did square roots before they had such aids. Don’t remember? Never learned? Watch the video below and learn a new skill.

The process is straightforward, but if you are a product of a traditional math education, you might find his terminology a bit confusing. He will refer to something like 18b meaning “a three-digit number where the last digit is b,” not “18 times b,” as you might expect.

If you think the first few examples are a little convenient, don’t worry. The video gets harder as you go along. By the end, you’ll be working with numbers that have fractional parts and whose square roots are not integers.

Speaking of the last part, stay tuned for the end, where you’ll learn the origin of the algorithm and why it works. Oddly, its origin is a Sanskrit poem. Who knew? He also talks about other ways the ancients computed square roots. As for us, we’ll stick with our slide rule.