GROUNDWORK · THE KIT

The Formula Board

Every rule the plots and drills lean on. One board, no guessing.
Signed additionSame signs: add the sizes, keep the sign. Different signs: subtract the sizes, take the sign of the larger size.
Signed subtractionSubtracting a number is adding its opposite.
Signed multiplication and divisionEven count of negative signs: positive result. Odd count: negative result.
Absolute valueDistance from zero. Never negative.
Order of operationsParentheses, then exponents, then multiply and divide left to right, then add and subtract left to right.
Distributive propertya(b + c) = ab + ac. The outside multiplies every inside term.
Like termsCombine terms whose variable parts match exactly: add the coefficients.
One-step equationsUndo the one operation with its opposite, on both sides.
Two-step equationsUndo the add or subtract first, then undo the multiply or divide.
Fraction additionMatch the denominators, add the numerators, simplify.
Fraction multiplicationMultiply straight across, then reduce.
GCF and LCMGCF: the largest shared divisor. LCM: the smallest shared multiple. Their product equals the product of the two numbers.
Decimal additionLine up the points, add, bring the point straight down.
PercentPercent means per hundred. To find p percent of n, multiply n by p over one hundred.
Ratio and unit rateA ratio compares by division. A unit rate is the amount per exactly one.
ProportionTwo equal ratios. Cross products are equal.
Exponents and rootsAn exponent counts repeated multiplication. A square root undoes a square.
Perimeter and area of a rectanglePerimeter: double the sum of length and width. Area: length times width.
The coordinate planeOrdered pairs read across then up. Quadrants count counterclockwise from where both are positive.