Guides and explainers for math, finance, and unit conversion — linked to the calculators and formulas you can use right away.
29 articles
8 matches
Math guides·12 min read
A practical guide to percents as ratios out of 100 — with formulas, worked examples, and the mistakes that trip people up.
Math guides·11 min read
Evaluate expressions consistently: parentheses first, then exponents, then multiply/divide left to right, then add/subtract left to right.
A practical guide to the three common averages: arithmetic mean, median, and mode — and how to choose the right one for your data.
A practical guide to fraction arithmetic: equivalent fractions, common denominators, and the rules for +, −, ×, and ÷.
A practical guide to writing ratios, setting up proportions, and solving for an unknown when two ratios are equal.
Percent change measures growth or decline from an original value; percent difference compares two values without treating one as “before.”
Math guides·10 min read
A practical guide to rounding decimals and counting significant figures so your answers match the precision of your measurements.
A clear guide to area as covering space in square units — with the main school formulas, worked examples, and pitfalls when units or heights go wrong.