Mathematics: Number Sense, Algebra, Geometry, and Data
What the Mathematics section asks
TASC math covers arithmetic with rational numbers, ratios and proportions, percentages, expressions and equations, functions, geometry, measurement, and statistics. Questions are mostly word problems, so translation from language to symbols matters as much as computation.
Concepts to master
Order of operations (parentheses, exponents, multiply/divide, add/subtract). Fraction and decimal operations, including converting among fractions, decimals, and percents. Proportional reasoning and unit rates. Solving linear equations and inequalities, remembering to reverse the inequality sign when multiplying or dividing by a negative. Slope as rise over run. Area and perimeter of rectangles, triangles, and circles; volume of prisms and cylinders. Mean, median, mode, and range, and reading tables and graphs.
Traps to expect
- Unit mismatches: minutes versus hours, centimeters versus meters. Convert before computing.
- Percent increase versus percent of: a 20% discount then a 10% discount is not 30% off.
- Inequality reversal when dividing by a negative number.
- Perimeter versus area confusion in word problems about fencing versus covering.
- Mean versus median when outliers pull the average.
Rule of thumb
Write the formula first, substitute known values, then solve. Estimate the answer before calculating; if your result is far from the estimate, recheck the setup rather than the arithmetic.
Worked example
A jacket costs $80 and is discounted 25%, then tax of 8% is added. Discount: 0.25 × 80 = $20, so the price is $60. Tax: 0.08 × 60 = $4.80. Total: $64.80. A common error is applying tax to $80, which gives $66.40 and is incorrect because tax applies to the discounted price.