A number expressed as a fraction of 100, used to describe proportions and rates of change.
A percentage represents a number out of 100. The word comes from Latin "per centum" meaning "by the hundred."
What is 15% of 200? → 200 × 0.15 = 30
25 is what percent of 80? → (25 ÷ 80) × 100 = 31.25%
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.
The inverse of exponentiation — the logarithm of a number tells you the exponent needed to produce that number from a given base.