Essential Math Cheat Sheet: Integers, Decimals, and Properties

Classified in Mathematics

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Math Reference Cheat Sheet

Rules for Multiplying and Dividing Integers

Same signs: PositiveDifferent signs: Negative
(+) & (+) = (+)(+) & (-) = (-)
(-) & (-) = (+)(-) & (+) = (-)

Special Rules for Integers

  • Even amount of negative integers: Product/quotient is positive.
  • Odd amount of negative integers: Product/quotient is negative.

Classifying Decimals

  • Terminating decimals: Have a remainder of zero; the decimal stops.
  • Non-terminating decimals: Continue infinitely.
    • Repeating: Continues infinitely and repeats a pattern (denoted by bar notation). Examples: 0.333..., 0.49090..., 0.166...
    • Non-repeating: Continues infinitely but does not repeat a pattern. Examples: Pi (π) and Euler's number (e).

Calculating Percent Error

% Error = [(Estimated Value - Actual Value) ÷ Actual Value] x 100

Mathematical Properties

Addition PropertiesMultiplication Properties
Commutative: Changing the order of addends does not change the sum.
  • -3 + 7 = 7 + (-3) = 4
Commutative: Changing the order of factors does not change the product.
  • -3 * 7 = 7 * (-3) = -21
Associative: Changing the grouping of addends does not change the sum.
  • (-5 + 6) + 4 = -5 + (6 + 4) = 5
Associative: Changing the grouping of factors does not change the product.
  • (-3 * 5) * 2 = -3 * (5 * 2) = -30
Additive Identity: The sum of any number and zero equals that number.
  • -31 + 0 = -31
Multiplicative Identity: The product of any number and 1 equals that number.
  • -107 * 1 = -107
Additive Inverse: The sum of any number and its opposite equals zero.
  • 51 + (-51) = 0
Multiplicative Inverse: The product of any number and its reciprocal equals 1.
  • 2 * ½ = 1
  • 3⁄8 * 8⁄3 = 24⁄24 = 1
-Zero Property: The product of any number and zero equals zero.
  • -9.99 * 0 = 0
-Distributive Property: Multiply the outside factor by each addend inside the parentheses.
  • -1(7 + 2) = -7 - 2 = -9
  • 3(5 + 8) = 15 + 24 = 39

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