Percentage Calculator Guide: Four Core Formulas and Where People Get It Wrong
The four percentage problem types, percentage points vs percentages, the stacked discount problem, and tipping math shortcuts.
Explore our collection of articles and guides in this category.
The four percentage problem types, percentage points vs percentages, the stacked discount problem, and tipping math shortcuts.
Adding, subtracting, multiplying, and dividing fractions with worked examples, fraction/decimal/percent conversion table, and the Python Fraction class.
The GPA formula (weighted average by credit hours), the full 4.0 scale table with letter grades, worked calculation example, and what GPAs mean to employers.
PRNG vs TRNG vs CSPRNG, the Mersenne Twister, why Math.random() is not cryptographically secure, and the Debian 2008 OpenSSL key generation bug.
log vs ln distinction, sin(90) in radians ≠ 1 (the most common trig error), implied multiplication ambiguity in PEMDAS, and scientific notation EE key.
All four percentage problem types, why 50% off then 20% off is 60% total (not 70%), percentage points vs percent, and the markup vs margin denominator difference.