Mathematics
Mathematics
The mathematics subtest covers arithmetic, fractions, decimals, percentages, ratios and proportions, measurement conversions, basic algebra, and geometry, often in practical or health-related contexts. Accuracy depends on setting up the problem before calculating.
Core rules
- Follow order of operations. Parentheses, exponents, multiplication/division left to right, then addition/subtraction left to right.
- Use unit analysis. Write units into the setup so unwanted units cancel. Convert milligrams to grams or milliliters to liters before combining numbers.
- Percent problems: part = whole × rate. A percent increase uses the original amount as the base; a percent decrease uses the original amount, not the result.
- Ratios: distinguish parts from total parts. A 1:4 concentrate-to-water mix has 5 total parts.
- Proportions: set corresponding quantities in the same positions, then cross-multiply.
Worked example
A solution is mixed as 1 part concentrate to 4 parts water. How much concentrate is needed for 300 mL of solution? Total parts = 1 + 4 = 5. Each part = 300 ÷ 5 = 60 mL. Concentrate = 1 × 60 = 60 mL; water = 4 × 60 = 240 mL. Check: 60 + 240 = 300 mL.
Traps
Treating 1:4 as 1 part in 4 rather than 1 part to 4; using the new value as the base for a percent change; rounding before the final step; and mixing units such as milligrams and milliliters without a conversion factor.