Working with money

The everyday math

Cashiers, bank tellers and bookkeepers count, check and balance money all day. For cashiers, O*NET rates "Issue receipts, refunds, credits, or change due to customers" at 92 out of 100 for importance, and lists counting the cash drawer at the start of a shift and reconciling payments with total sales.¹ Retail salespeople "Compute sales prices, total purchases, and receive and process cash or credit payment" (89).² Four of a bank teller's highest-rated tasks, each rated 95, are about counting, balancing or checking money, including paying out after "verifying that ... written and numerical amounts agree".³ Bookkeeping clerks "Check figures, postings, and documents for correct entry, mathematical accuracy, and proper codes" (92) and "Perform financial calculations, such as amounts due, interest charges, balances, discounts" (83).⁴

The UK National Careers Service names "maths knowledge" as a skill for sales assistants, financial services customer advisers and bookkeepers.^5,6,7 Calculator rule: there is no official test for these jobs; employers set their own, so ask the employer.

The skills behind it, built around science

In a classic study from 1985, young people working in street commerce in Recife, Brazil, did better on problems set in real sales than on school-type word problems and bare sums with the same numbers, and they used their own strategies rather than school methods.⁸ It is a lovely reminder that everyday arithmetic is real math. From case studies in manufacturing and financial services, the authors of a scholarly book argue that work now depends more and more on making sense of the figures software produces, rather than only calculating them.⁹

Counting change and checking a total is mostly adding and taking away. Add & Subtract practises those facts, and Mental Math Master reads each sum aloud so you hold the numbers in your head.

• Classic workouts
• Mental Math Master

Honest limits