The inverse of exponentiation — the logarithm of a number tells you the exponent needed to produce that number from a given base.
A logarithm answers the question: "What power must I raise the base to, to get this number?" If b^x = y, then log_b(y) = x.
log(a×b) = log(a) + log(b) | log(a/b) = log(a) − log(b) | log(a^n) = n·log(a)
A number expressed as a fraction of 100, used to describe proportions and rates of change.
A measure of the spread or dispersion of a data set from its mean (average).
Three measures of central tendency used to describe the center of a data set.
A fundamental relation in geometry: the square of the hypotenuse equals the sum of squares of the other two sides.
Area measures the surface inside a shape (in square units); perimeter measures the distance around it.
A number representing a part of a whole, written as a numerator over a denominator.