CBEST Mathematics: Arithmetic, Algebra, Geometry, and Data
Core concepts
The Mathematics section emphasizes estimation, numerical relationships, measurement, geometry, statistics and probability, and word problems. You should be comfortable with fractions, decimals, and percents; ratios and proportions; order of operations; unit conversions; perimeter, area, and volume; angle relationships; mean, median, mode, and range; simple probability; and translating sentences into equations. A calculator is not provided, so estimation and mental math matter.
Common traps
- Unit mismatch: minutes vs. hours, centimeters vs. meters, or “per day” vs. “per week.”
- Percent language: “25% more than” is not the same as “25% of”; percent increase uses the original amount as the base.
- Average speed: total distance divided by total time, not the average of two speeds.
- Partial answers: an answer choice may be an intermediate result, such as the discount rather than the final price.
- Misread negatives: “not,” “except,” and “least” change the question.
Rule of thumb
Estimate first, compute second, and check that the answer is reasonable. For multiple-choice algebra, plug choices back into the equation. Always label units.
Worked example
A jacket costs $80. It is discounted 25%, then 8% tax is added. What is the total? Discount: $80 × 0.25 = $20, so sale price = $60. Tax: $60 × 0.08 = $4.80. Total = $64.80. A common trap is adding tax to $80 or subtracting $20 from the taxed price.