Guides
- APR, APY, nominal and effective rates: what is the difference?Why a loan and a savings account can both say “5 %” and still mean different things, and how to compare rates fairly.
- How mortgage amortization worksWhy early mortgage payments are mostly interest, how equity builds over time, and what extra payments really do.
- Percentage change, percentage difference and percentage pointsThree ways to compare numbers with percentages — and the common mistakes that make statistics misleading.
- What BMI can and cannot tell youHow body mass index is calculated, why it is used for populations, where it misleads individuals, and what to look at alongside it.
- Time zones and daylight saving: why some times do not existHow UTC offsets change through the year, why some local times are skipped or repeated, and how to convert meeting times safely.
- IPv4 subnetting basics: reading an address and a prefixWhat /24 means, how network and broadcast addresses are found, and how to size a subnet for a number of devices.