Key Terms
Natural Numbers
Counting numbers. {1, 2, 3, ...} Whole Numbers: naturals plus zero.
Irrational Numbers
Cannot be written as a fraction; decimal never terminates or repeats. Real Numbers: all rationals and irrationals combin
Commutative (addition)
A + b = b + a Commutative (multiplication): a * b = b * a Order does not matter. Addition and multiplication only; not s
Associative (addition)
A + (b + c) = (a + b) + c Associative (multiplication): a * (b * c) = (a * b) * c Grouping does not matter. Addition and
Distributive
A * (b + c) = a*b + a*c The only property that bridges addition and multiplication. Also works for subtraction inside th
Identity (addition)
A + 0 = a. Zero is the additive identity.
Inverse (addition)
A + (-a) = 0. Every number has an opposite.
Constant
A fixed value that does not change. Example: 5 in x + 5.
Variable
A quantity that can take different values. Example: x, m, r.
Algebraic Expression
Constants and variables combined with +, -, *, /.
Example
Surface area of a cylinder, S = 2*pi*r(r + h), with r = 6 and h = 9. S = 2*pi*(6)*(6 + 9) = 2*pi*(6)*(15) = 180*pi squar
Exponent
Tells how many times the base is multiplied by itself.
Exponential Notation
Shorthand for repeated multiplication. a^n means a multiplied by itself n times.
Equation
A statement that two expressions are equal. Example: 2x + 1 =