Practical guides
Clear explanations with examples, linked to the tools that do the math.
- Academic writing
How to Cite in APA 7th Edition
A practical guide to citing websites, books, and journal articles in APA 7, with current rules, examples, and the mistakes to avoid.
Read guide - Personal finance
How to Make a Personal Budget
A step-by-step method for building a simple, realistic monthly budget you can actually keep, including how to use the 50/30/20 rule.
Read guide - Personal finance
Compound Interest Explained
What compound interest is, how to calculate it, and why time, rate, and regular contributions change your final balance so much.
Read guide - Math
How to Calculate Percentages
Learn to find percentages, discounts, increases, and percentage change with simple formulas and clear everyday examples.
Read guide - Dates and deadlines
How to Calculate Business Days and Dates
The difference between calendar days and business days, when to include start and end dates, and how to avoid common date-counting errors.
Read guide - Measurement and conversion
A Basic Guide to Unit Conversion
Essential concepts for converting length, mass, volume, and temperature accurately, with the right factors and sensible rounding.
Read guide