Mathematics: Arithmetic, Algebra, Geometry, and Data
The Mathematics domain covers number and quantity (fractions, decimals, percents, ratios, proportions), algebra (solving and setting up linear equations, interpreting expressions), geometry (perimeter, area, volume, angles, similar figures), and statistics and probability (mean, median, mode, range, simple probability, reading tables and graphs). You also need word-problem translation-turning a described situation into an equation-and estimation to check reasonableness.
Common traps: answering the wrong quantity (finding a discounted price when asked for the discount), forgetting to convert units, confusing percent of with percent increase, mixing up mean and median when outliers are present, and misreading a graph's scale. On geometry, remember that similar figures scale lengths proportionally but areas by the square of the scale factor. Always check whether the question asks for an exact value or an estimate.
Rule of thumb: write down what is given, what is asked, and one equation linking them before computing. Then sanity-check: is the answer plausible in size and sign?
Worked example: A $40 item is discounted 25%, then tax of 10% is added. Discount: 0.25 × 40 = 10, so price is $30. Tax: 0.10 × 30 = 3. Total: $33. Note the tax applies to the discounted price-applying it to $40 would wrongly give $34.