Mathematics
What to know
The math section covers arithmetic with fractions, decimals, and percents; ratios and proportions; order of operations; exponents; algebraic expressions and equations; inequalities; linear functions and slope; systems of equations; geometry (perimeter, area, volume, angles, Pythagorean theorem); coordinate geometry; statistics (mean, median, mode, range); probability; and unit conversion. Most problems are one or two steps, so accuracy with signs and units matters more than speed.
Traps
Negative signs cause many errors, especially when distributing: -3(x - 4) = -3x + 12, not -3x - 12. Distinguish percent of from percent increase or decrease. Percent change = (new - old) / old. Check whether a question asks for radius or diameter, perimeter or area, and whether the graph's axis starts at zero. Answers must match the units requested. When an equation looks messy, plug answer choices back in.
Worked example
Solve 3(x - 4) = 18. Distribute: 3x - 12 = 18. Add 12: 3x = 30. Divide by 3: x = 10. Check: 3(10 - 4) = 3(6) = 18. Rule of thumb: undo operations in reverse order (add/subtract first, then multiply/divide), and always substitute your answer to verify. For a 15% tip on $48, multiply 48 by 0.15 to get $7.20.