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Blog — Math

Guides, worked examples and explainers.

Math

Standard Deviation Explained in Plain English

Standard deviation measures how spread out your data is. Here is what it really means, how to calculate it, and how to interpret the number you get.

May 5, 2026 Math

Extending the Distance Formula to 3D and Higher Dimensions

The 2D distance formula generalizes cleanly to 3D and beyond. Here is what it looks like in higher dimensions and where you encounter it.

May 4, 2026 Math

How to Find Square Roots by Hand (When Your Calculator Is Not Available)

Calculators are not always available. Here are three reliable methods to find square roots without one — including the algorithm taught before pocket calculators.

May 3, 2026 Math

Prime Factorization Made Easy: A Step-by-Step Guide

Every whole number has a unique prime "fingerprint." Here is how to find it with a factor tree, why it matters, and how it powers GCF, LCM, and fractions.

May 2, 2026 Math

Mean vs Median vs Mode: Which Average Should You Use?

Three numbers all called "the average" — but each tells a different story. Here is when to use mean, median, and mode, with real examples.

May 1, 2026 Math

Completing the Square: The Technique Behind Half of Algebra

Completing the square shows up in the quadratic formula, conic sections, integrals, and optimization. Here is how it works — and why.

Apr 30, 2026 Math

Percent Change vs Percentage Points: The Confusion That Misreads Every News Story

A rate going from 5% to 6% is a 1 percentage point increase and a 20% increase. Both are true. Confusing them changes the story entirely.

Apr 29, 2026 Math

TI-84 vs TI-Nspire vs Casio fx-9750: Which Calculator Should You Buy?

The TI-84 dominates U.S. high schools, but the TI-Nspire is more powerful and the Casio fx-9750 is half the price. Here is which one fits your needs.

Apr 28, 2026