ISEE Quantitative Reasoning cheat sheet
ISEE Quantitative Reasoning · Keep the key ideas within reach.
Mathematics Achievement
Order of operations: parentheses, exponents, multiplication and division left to right, then addition and subtraction left to right.
Rules of exponents: x^a · x^b = x^(a+b); x^a ÷ x^b = x^(a−b); (x^a)^b = x^(ab); x^0 = 1 for x ≠ 0; x^(−a) = 1/x^a.
Slope of a line through (x1, y1) and (x2, y2) is (y2 − y1)/(x2 − x1); slope-intercept form is y = mx + b.
Area formulas: rectangle lw, triangle ½bh, circle πr²; circumference 2πr; Pythagorean theorem a² + b² = c² for right triangles.
Factor a quadratic by finding two numbers whose product is the constant term and whose sum is the coefficient of the middle term.
Sum of interior angles of a polygon = (n − 2) × 180°; each exterior angle of a regular n-gon measures 360°/n.
Volume: rectangular prism lwh, cylinder πr²h; surface area of a rectangular prism = 2(lw + lh + wh).
To solve a system of two linear equations, substitute one equation into the other or add/subtract the equations to eliminate a variable.