MCAS Math Grade 4 cheat sheet

Place value: in a number, each place is 10 times the place to its right; 7 in 7,482 means 7,000, while 7 in 4,782 means 700.

Rounding rule: look at the digit one place to the right of the target place; 5 or more rounds up, 4 or less keeps the digit and zeros the rest.

Multi-digit multiplication: 24 × 36 = 24 × 30 + 24 × 6 = 720 + 144 = 864 (partial products).

Division check: quotient × divisor + remainder = dividend; the remainder must be less than the divisor.

Fraction equivalence: multiplying or dividing numerator and denominator by the same nonzero number keeps the value; 2/3 = 8/12.

Comparing fractions: same denominator, compare numerators; same numerator, the smaller denominator is the larger fraction (1/4 > 1/7).

Adding and subtracting fractions with like denominators: operate on numerators only and keep the denominator; 3/8 + 2/8 = 5/8.

Decimal place value: 0.47 = 4 tenths + 7 hundredths = 47/100; 0.4 = 0.40, so 0.4 = 0.40 in value.

Measurement conversions: 1 km = 1,000 m, 1 m = 100 cm, 1 kg = 1,000 g, 1 L = 1,000 mL, 1 hr = 60 min, 1 min = 60 sec.

Angle benchmark: a right angle measures 90°; angles less than 90° are acute, greater than 90° (and less than 180°) are obtuse.

Lines: parallel lines never meet and stay the same distance apart; perpendicular lines meet at a right angle; intersecting lines cross at one point.

Triangle classification by angles: all acute, one right, or one obtuse; by sides: equilateral (3 equal), isosceles (2 equal), scalene (none equal).

Area of a rectangle = length × width; perimeter = 2 × (length + width); a square with side s has area s² and perimeter 4s.

Composite figures: split into non-overlapping rectangles, find each area, then add the parts.

Line plot with fractional units: each X stands for one data value; the total is the sum of all marked values, and the most frequent value is the mode.

Pattern rule: find the change between consecutive terms; for 3, 7, 11, 15 the rule is add 4, so the next term is 19.

Multi-step word problems: identify the unknown, choose operations in order, and check the answer against the units asked for.