Mathematics
What to know
The Mathematics domain emphasizes number sense, operations, fractions, geometry, measurement, data, and algebraic reasoning. Know place value and regrouping, properties of operations, order of operations, factors and multiples, and integer relationships. For fractions, understand equivalence, comparing with common denominators or benchmarks, and the meaning of multiplication and division. Geometry includes angle types, polygon properties, symmetry, perimeter, area, and volume. Measurement includes unit conversions and choosing appropriate units. Data includes mean, median, mode, range, and reading graphs. Algebraic thinking includes patterns, expressions, equations, and the meaning of variables.
Traps
Area versus perimeter: area is square units covering a region; perimeter is linear units around it. When converting, multiply when going from larger to smaller units and divide when going from smaller to larger. In order of operations, multiply and divide before adding and subtracting, left to right. Mean is affected by outliers; median is not.
Worked example
Divide 3/4 ÷ 1/2. Keep-change-flip: 3/4 × 2/1 = 6/4 = 3/2, or 1 1/2. Check by reasoning: how many halves fit in three-fourths? One full half fits, with one-fourth left-half of a half-so 1 1/2.