Work asks the same maths questions over and over, and nobody sits you down and explains them. What margin are we actually making on this? Is that a rise or a fall, and by how much? How many do we have to sell before the month stops costing us money? Why is the number on the payslip so much smaller than the number in the offer letter? The Work Math Workout is the practice book for all of it — the arithmetic behind the decisions you are already being asked to make.
Every problem is drawn from real working life. Every answer is worked out in full, at the end of the chapter it belongs to — not buried in the back of the book. No jargon, no spreadsheet required, and no assumption that you did well at maths at school.
What's inside — 7 chapters plus a closing capstone, 449 practice problems, every answer worked:
- Markup, Margin & Pricing — the same profit gives two different percentages, and quoting the wrong one costs money
- Percentage Change & Business Growth — always divide by the old value, and why +20% then −20% does not get you back
- Break-Even & Cost Analysis — contribution margin, the break-even point, and what moves it
- Invoices, Payroll & Billing — gross to net, overtime, hourly against salary, and an invoice that adds up
- Reading Charts & Business Data — five questions to ask before you believe a picture
- Workplace Statistics — when the mean lies, when the median tells the truth, and how to weight an average properly
- Business Problem Solving & Logic — ROI, payback, sunk cost, opportunity cost, and comparing two options honestly
- One Business Day, Every Skill — a closing capstone chapter that chains every skill into one running story, with a full walkthrough
Five ways to practise each idea: A Warm-Up gets you moving with one-step questions. Standard problems build the mechanic. Word problems put it into a real workplace. Mental-math challenges keep the shortcut sharp for the meeting where you cannot reach for a calculator. "Explain It" prompts make sure you actually understand — not just memorise.
Seven free companion calculators — no sign-up, nothing to install. Every chapter is paired with a free online tool at the companion site: a markup-and-margin converter, a percentage change calculator, a break-even calculator, a gross-to-net pay estimator, a chart checker that draws your numbers on an honest axis and a truncated one side by side, a mean/median/mode tool with weighted averages, and an ROI and payback calculator. Same math as the book — just faster at your desk. Plus a free printable toolkit with a worksheet for every chapter.
Written for anyone who has ever nodded along in a meeting. You do not need a business background. If you can add, subtract, multiply, and divide, you can do every problem in this book — and you will read the next set of numbers put in front of you with a good deal more confidence.
Educational, not advisory. This book teaches the arithmetic behind business and workplace numbers. It is not financial, tax, legal, or accounting advice. Tax rates, payroll deductions, and statutory overtime rules vary by country and change over time — the examples use illustrative rates; substitute your own. The arithmetic itself is universal.
This book was written in collaboration with AI tools. Every worked example, exercise answer, and formula was independently checked before publication — so what you see on the page is the arithmetic the book actually teaches.
Expanded & corrected printing — August 2026. Every problem in this book was re-verified against an independent arithmetic check. That pass corrected one answer-key entry in the percentage-change chapter and tidied a crowded label, etc.
The math behind a working week is a small, friendly set of skills. This is your workout for it.
