Blog
Deeper educational articles and practical math explainers. For evergreen how-tos and reference pages, see Study Guides.
Practical math
Compound Interest: How Growth Actually Stacks
Why adding 5% ten times is not the same as compounding, with worked money examples.
Updated October 2, 2026
Algebra
The Quadratic Formula: Roots and the Discriminant
Solve ax² + bx + c = 0 with the formula, read the discriminant, and check answers.
Updated October 2, 2026
Number sense
Scientific Notation: Large and Small Numbers Clearly
Write, read, and convert scientific notation—without mixing it up with calculator e-notation mistakes.
Updated October 2, 2026
Calculator skills
Order of Operations: Avoid These Calculator Pitfalls
Brackets, powers, and left-to-right rules—with the typed expressions that quietly change the answer.
Updated October 2, 2026
Combinatorics
Combinations vs Permutations: nCr and nPr
When order matters and when it doesn’t, with calculator checks for nCr and nPr.
Updated October 2, 2026
Statistics
Mean, Median, or Mode? Choosing the Right Average
When each measure fits—and how one outlier can pull the mean off course.
Updated October 2, 2026