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 2026-10-29

• Working with Fractions

  Simplifying, comparing, converting and calculating with fractions — worked examples you can follow, from common denominators to decimals.

  Updated 2026-09-05

• The Pythagorean Theorem

  What a² + b² = c² means, when the theorem applies, and three classic right-triangle examples worked one clear step at a time.

  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 2026-10-29

• 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 2026-10-29

• LCM and GCF, side by side

  How the greatest common factor and the least common multiple are found, where each one matters in real problems, and the identity that links them.

  Updated 2026-10-30

• Clock Arithmetic (Modular Math)

  Remainders as a number system: why 17 mod 5 = 2, how clock wrapping works, and where modular thinking powers divisibility rules, hashing, and cryptography.

  Updated 2026-10-30