3.1 Money, Work, and Measurement Math
Key Takeaways
- CASAS math is functional: the numbers usually come from a receipt, pay stub, label, schedule, chart, or workplace note.
- Percent, unit price, gross pay, net pay, overtime, averages, rates, and measurement should be solved with the document's units before choosing an answer.
- Gross pay is earnings before deductions; net pay is take-home pay after taxes, benefits, and other deductions.
- Reasonableness checks catch common CASAS traps, such as choosing a discount amount instead of a sale price or forgetting to subtract unpaid break time.
- Measurement and rate questions often test whether the learner can match units, convert simple quantities, and decide whether the answer makes practical sense.
Functional Numeracy Starts With the Document
CASAS math questions usually begin with a real-life document: a sale sign, receipt, utility bill, pay stub, work schedule, food label, recipe, mileage note, or measurement instruction. The test is not asking for math in isolation. It is asking whether you can choose the right numbers from the document, use the correct operation, and give an answer that fits the situation.
Use the same four-step routine for most CASAS numeracy tasks:
- Read the question first. Decide what the answer must represent: total cost, sale price, net pay, average, rate, length, weight, time, or amount left.
- Circle only the needed numbers. Ignore extra dates, names, fees, or labels that do not answer the question.
- Match the units. Dollars, hours, pounds, ounces, miles, minutes, inches, feet, and servings cannot be mixed without conversion.
- Estimate before selecting. A quick estimate should make the final answer feel possible.
Core CASAS Math Moves
| Task | Setup | Operation | Reasonableness check |
|---|---|---|---|
| Percent discount | $80 jacket, 25% off | 80 x 0.25 = 20 discount; 80 - 20 = 60 sale price | Sale price must be less than original price |
| Unit price | $7.50 for 3 pounds | 7.50 / 3 = $2.50 per pound | Unit price is smaller than the package price |
| Gross pay | 32 hours at $18/hour | 32 x 18 = $576 | Before deductions, so it should be higher than net pay |
| Net pay | $576 gross, $91 deductions | 576 - 91 = $485 | Take-home pay is lower than gross pay |
| Overtime | 43 hours, $16/hour, overtime after 40 at 1.5x | 40 x 16 + 3 x 24 = $712 | Overtime hours use a higher hourly rate |
| Average | 54, 61, 59 items | (54 + 61 + 59) / 3 = 58 | Average should fall between low and high values |
| Rate | 180 miles in 3 hours | 180 / 3 = 60 miles per hour | Rate uses the word per: miles per hour |
| Measurement | 2.5 feet of trim per shelf, 4 shelves | 2.5 x 4 = 10 feet | Final unit should match the question |
Percent and Sale Price
Percent means per hundred. Convert the percent to a decimal before multiplying: 10% = 0.10, 25% = 0.25, and 50% = 0.50. For a discount, first find the discount amount, then subtract it from the original price. For tax or a fee, find the added amount, then add it to the price.
A common wrong answer is the discount amount itself. If a $48 item is 25% off, $12 is the discount, not the final price. The sale price is $36.
Unit Price, Rates, and Averages
Unit price and rate both use division. Unit price asks for cost per item, per ounce, per pound, or per gallon. Rate asks for an amount per unit of time, distance, or work, such as miles per hour or boxes per hour.
An average is the total divided by the number of values. CASAS may use averages in workplace production, weekly hours, daily sales, temperatures, or spending. Add all values first, then divide by the count. Do not divide by a number from the document unless it is the number of values being averaged.
Gross Pay, Net Pay, and Overtime
On a pay stub, gross pay is earned before deductions. Net pay is the amount actually received after taxes, insurance, retirement, uniforms, or other deductions are subtracted. If the question asks for take-home pay, look for net pay or calculate gross minus total deductions.
Overtime questions require two calculations. Regular pay covers the regular hours, often 40 hours per week. Overtime pay covers only the extra hours, often at one and one-half times the regular hourly rate. Calculate regular and overtime pay separately, then add them.
Measurement and Unit Checks
Measurement tasks may involve length, weight, volume, temperature, time, or distance. The safest move is to write the unit beside every number. If a recipe needs 3/4 cup per batch and the worker makes 4 batches, multiply 3/4 by 4 to get 3 cups. If a label says a cleaner needs 2 ounces per gallon and the bucket holds 3 gallons, multiply 2 by 3 to get 6 ounces.
When answer choices have different units, the unit may decide the question before the arithmetic does. An answer in inches cannot be correct if the question asks for feet unless the conversion has already been done.
Final Check Before Choosing
Ask three questions before selecting an answer:
- Did I answer the exact thing asked, such as sale price instead of discount amount?
- Did I use the correct unit, such as per pound, per hour, or take-home pay?
- Is the number reasonable compared with the document?
This last step is especially important because CASAS distractors often come from one skipped step: adding when a discount should subtract, using total shift time instead of paid time, dividing by the wrong count, or forgetting that overtime applies only to extra hours.
A grocery sign says: Rice, 5-pound bag, $8.45. What is the unit price per pound, rounded to the nearest cent?
Maya earns $17 per hour. This week she worked 40 regular hours and 4 overtime hours paid at 1.5 times her regular rate. What is her gross pay before deductions?