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Guides

Short, clear guides that explain the maths behind dates, time and percentages, with worked examples and links to the right calculator.

Guides about Guides

Flat-vector staircase graphic titled "PEMDAS ORDER OF OPERATIONS" with five descending steps labeled P Parentheses, E Exponents, M Multiplication, D Division, A Addition, S Subtraction, showing the worked example 8 + 2 × 5 = 18. October 23, 2026 · 10 min read

How to Use PEMDAS: Order of Operations Explained

Learn PEMDAS order of operations with worked examples: parentheses, exponents, multiplication, division, addition…

 Flat-vector infographic with a clock in the center showing "1 hour = 60 minutes = 3,600 seconds," an hourglass card on the left, a stopwatch card on the right, and ×60 conversion arrows linking hour, minute, and second cards October 22, 2026 · 8 min read

How to Convert Time Units: Hours, Minutes & Seconds Explained

Learn how to convert time units with simple multiply-and-divide rules, a conversion table, and worked examples for…

 Flat-vector illustration titled "3:2 PROPORTION": a balance scale holding three blue circles on the left pan and two orange circles on the right, captioned "3 blue circles • 2 orange circles — Equal Balance — 3 Parts : 2 Parts" October 22, 2026 · 9 min read

How to Calculate Proportion: Cross-Multiplication with Examples

Learn how to calculate proportions with cross-multiplication: step-by-step examples of direct and inverse proportions…

 Illustration of a world map with clocks showing different times in major cities and arrows between time zones October 21, 2026 · 8 min read

How to Convert Time Zones: A Simple Guide with Examples

Learn how to convert time zones with a simple formula, step-by-step worked examples between major cities, and tips for…

 Flat-vector illustration of a ratio being simplified: the large figures 12:18 with an arrow pointing to 2:3, a division symbol and a small calculator icon, in teal and amber on a clean white background. October 21, 2026 · 8 min read

How to Calculate Ratio: Simplify and Solve with Examples

Learn how to calculate a ratio step by step: simplify with the GCD, build equivalent ratios, and solve missing values…

 Flat-vector illustration of a number line with arrows showing rounding rules. October 20, 2026 · 9 min read

How to Round Numbers: Rules for Rounding Up and Down

Learn how to round numbers with simple rules: to the nearest ten, hundred, thousand, and decimal places. Includes the…

 Flat-vector illustration of a 24-hour military clock face next to a military-to-standard time conversion chart. October 20, 2026 · 8 min read

How to Read Military Time: Convert Military Time to Standard Time

Learn how to read military time with a full 24-row conversion chart, pronunciation rules, and worked examples from 0000…

 Flat-vector illustration of fraction equations beside a pizza showing three quarters. October 19, 2026 · 7 min read

How to Calculate Fractions: Add, Subtract, Multiply & Divide Step by Step

Learn how to calculate fractions step by step: add, subtract, multiply, divide, simplify, and compare fractions with…

 Flat-vector illustration showing a $100 price plus 20% VAT combining into a $120 total. October 19, 2026 · 7 min read

How to Calculate VAT: Price with Tax Formula & Examples

Learn how to calculate VAT: add tax with net × (1 + rate), extract it with gross ÷ (1 + rate). Worked examples and…

 Flat-vector illustration converting an hourly wage tag into an annual salary stack. October 18, 2026 · 8 min read

How to Convert Hourly Wage to Annual Salary: Formula with Examples

Learn how to convert your hourly wage to an annual salary: hourly pay × hours per week × 52. Includes part-time…

 Illustration of two calendars with an arrow between them showing how to calculate the number of days between two dates October 18, 2026 · 7 min read

How to Calculate Days Between Two Dates: Step-by-Step Guide with Examples

Learn how to calculate days between two dates by hand: month-by-month method, inclusive vs exclusive counting, leap…

 Illustration of a clock with a 1.5x badge representing overtime pay October 17, 2026 · 5 min read

How to Calculate Overtime Pay: Time and a Half Explained with Examples

Learn how to calculate overtime pay: the 1.5x time-and-a-half rule, weekly vs daily overtime, salaried workers, and…