Math Formulas I Actually Use in Real Life
School taught me dozens of formulas I never used. It also taught me a few I use constantly. Here are the ones that genuinely come up. School taught me dozens of math formulas I never used again. It also taught me a few I use constantly, though I did not realize it at the time. After years of managing a household budget, planning projects, and cooking, I have a short list of formulas that genuinely come up. Here they are, with the contexts where I use them and the mistakes I made before I got them right. Area and Volume for Home Projects When I painted my apartment, I needed to know how much paint to buy. The formula is simple: wall area equals height times width, minus the area of doors and windows. My walls totaled about 90 square meters. A liter of paint covers roughly 10 square meters, so I needed about 9 liters for one coat. Buying for two coats meant 18 liters. I rounded up to 20 and had a little left over, which was better than running out mid-wall. Volume comes up when buying soil for planters, concrete for a small pad, or storage containers. A rectangular box has volume of length times width times height. A 50 by 30 by 20 centimeter planter has a volume of 30,000 cubic centimeters, which is 30 liters.