An *obtuse angle* is bigger than

An *odd number* is an *integer* that is not *divisible* by 2. The odd numbers are

*Operation* is the process of combining numbers or expressions. In the primary years, operations include addition, subtraction, multiplication, and division. In later years, operations include, for instance, raising to a power, taking the logarithm, and more complex operations, such as integration.

*Order of operations* refers to a collection of rules for simplifying expressions. It stipulates that calculations in brackets must be made first, followed by calculations involving *indices* (*powers*, *exponents*), then multiplication and division (working from left to right), and lastly, addition and subtraction (also in order from left to right); for example, in *operations* are performed in the order they are written, the incorrect result, 6.5 is obtained.

In mathematics, an *ordered pair* is a collection of two numbers whose order is significant. Ordered pairs are used to describe the location of a point in the *Cartesian plane*.

An outlier is a data value that appears to stand out from the other members of the data set by being unusually high or low. The most effective way of identifying outliers in a data set is to graph the data; for example, in the following list of ages of a group of 10 people, {12, 12, 13, 13, 13, 13, 13, 14, 14, 14, 24}, the number 24 would be considered to be a possible outlier.