How do you Calculate the cube root of 7.2? - Answers

Here are four ways: (1). Take the log of 7. (You have to either look it up in a book, find it on a slide rule or calculator, or remember the infinite series definition of the log function and calculate the first 10 or 15 terms of the series.) Then take one third of the log. Then find the anti-log of the quotient. (2). There is a direct procedure to calculate the cube root of a number with a pencil and paper. Although I was working as a professional engineer before calculators and computers were generally available, I learned the pencil method for square roots, but not the one for cube roots. (3). Find the approximate cube root directly on a slide rule. (4). Use a hand-calculator, or a calculator simulator on a computer. These days, it's the only way that makes sense.