Math Guides

Short, original explanations of the concepts behind the calculators — each with worked examples.

• Percentages Explained Simply

  What percentages mean, how to calculate them, and the three percentage problems everyone should know.

  Updated 2026-09-01

• Working with Fractions

  Simplifying, comparing, converting and calculating with fractions — with worked examples.

  Updated 2026-09-05

• The Pythagorean Theorem

  How a² + b² = c² works, when to use it, and three classic right-triangle examples.

  Updated 2026-09-08

• Solving Quadratic Equations

  Factoring, completing the square, and the quadratic formula — plus what the discriminant tells you.

  Updated 2026-09-12

• Mean, Median & Mode

  The three measures of central tendency, when each is useful, and how outliers change the story.

  Updated 2026-09-15

• Order of Operations (PEMDAS)

  Why 2 + 3 × 4 is not 20 — the rules that keep everyone’s math consistent, with step-by-step examples.

  Updated 2026-09-18