A measure used to describe data; the mean, median, and mode are measures of central tendency.

Principal is the amount of money borrowed or invested.

Rectangular numbers are numbers that represent the total number of dots contained within a rectangular arrangement of dots with the number of columns being one more than the number of rows

When estimating, compatible numbers are numbers that are close in value to the actual numbers, and which make it easy to do mental arithmetic.

Estimation is a good tool for making a rough calculation.

A Keith Number is an n-digit integer N with the following property: If a Fibonacci-like sequence (in which each term in the sequence is the sum of the n previous terms) is formed, with the first n ter [..]

A knot is an embedding of a circle in 3-dimensional Euclidean space.

The horizontal label across the bottom and the vertical label along the side tells us what kinds of facts are listed in a graph.

Lateral faces are the faces in a prism or pyramid that are not bases.

A leading zero is any zero that leads a number string with a non-zero value.