Mathematics - Grade 4 MCAS
The Mathematics domain of the Grade 4 MCAS covers the full grade-4 curriculum: place value through 1,000,000, multi-digit multiplication and division, fraction equivalence and operations, decimal notation for fractions, measurement conversion, area and perimeter, angle measurement, symmetry, and data shown on line plots. Items come as multiple-choice, short-answer, and open-response questions. Open-response items are scored with a rubric, so a clearly labeled model, the work, and an answer with units can earn partial credit even when one calculation slips.
Core rules worth memorizing
- Multiplication: you must handle 4-digit × 1-digit and 2-digit × 2-digit. Split with partial products, then connect to the standard algorithm: 36 × 24 = 36 × 20 + 36 × 4 = 720 + 144 = 864.
- Division: divide up to 4 digits by 1 digit and interpret the remainder in context - drop it, round up, or write it as a fraction of the divisor.
- Fractions: a/b = (n × a)/(n × b) creates equivalent fractions; add and subtract only when denominators match; multiply a fraction by a whole number by multiplying the numerator.
- Decimals: compare to hundredths by place value, so 0.4 = 0.40, and 0.40 > 0.35.
- Measurement: 1 km = 1,000 m, 1 m = 100 cm, 1 kg = 1,000 g, 1 L = 1,000 mL, 1 lb = 16 oz, 1 hr = 60 min.
- Geometry: area = length × width, perimeter = 2(length + width); angles add, and a right angle measures 90°.
Worked example
Compute 4 × 3/5 and write the answer as a mixed number. Four groups of 3/5 means 3/5 + 3/5 + 3/5 + 3/5 = 12/5. Since 12 ÷ 5 = 2 remainder 2, the answer is 2 2/5. Check reasonableness: 3/5 is less than 1, so the product must be less than 4. On a written-response item, sketch four bars each shaded three-fifths, name the mixed number, and show the division.
Traps that cost marks
Adding denominators (2/5 + 1/5 = 3/5, not 3/10); confusing area with perimeter; rounding a halfway value down (4,550 to the nearest hundred is 4,600); converting in the wrong direction (meters to centimeters means multiplying by 100); reading the wrong protractor scale; and reporting a remainder as a plain number when the question asks what it means.