Teaching children geometric shapes numbers whose sum is 0 are additive inverses of one another. See Table 3 in this Glossary.

Example: a list of heights and weights for each player on a football team. A method of visually displaying a distribution of data values by using the median, quartiles, and extremes of the data set. A set of predefined steps applicable to a class of problems that gives the correct result in every case when the steps are carried out correctly. Purposeful manipulations that may be chosen for specific problems, may not have a fixed order, and may be aimed at converting one problem into another.

A strategy for finding the number of objects in a group without having to count every member of the group. For example, if a stack of books is known to have 8 books and 3 more books are added to the top, it is not necessary to count the stack all over again. A transformation that moves each point along the ray through the point emanating from a fixed center, and multiplies distances from the center by a common scale factor. A multi-digit number is expressed in expanded form when it is written as a sum of single-digit multiples of powers of ten. For a random variable, the weighted average of its possible values, with weights given by their respective probabilities. For a data set with median M, the first quartile is the median of the data values less than M.

2 See also: median, third quartile, interquartile range. The word fraction in these standards always refers to a non-negative number. Two probability models are said to be combined independently if the probability of each ordered pair in the combined model equals the product of the original probabilities of the two individual outcomes in the ordered pair. A number expressible in the form a or -a for some whole number a.

A measure of variation in a set of numerical data, the interquartile range is the distance between the first and third quartiles of the data set. See also: first quartile, third quartile. A method of visually displaying a distribution of data values where each data value is shown as a dot or mark above a number line. Also known as a dot plot. A measure of center in a set of numerical data, computed by adding the values in a list and then dividing by the number of values in the list. A measure of variation in a set of numerical data, computed by adding the distances between each data value and the mean, then dividing by the number of data values.

A measure of center in a set of numerical data. The median of a list of values is the value appearing at the center of a sorted version of the listâ€”or the mean of the two central values, if the list contains an even number of values. In the graph of a trigonometric function, the horizontal line halfway between its maximum and minimum values. Multiplication or division of two whole numbers with whole number answers, and with product or dividend in the range 0-100. Two numbers whose product is 1 are multiplicative inverses of one another. A diagram of the number line used to represent numbers and support reasoning about them. In a number line diagram for measurement quantities, the interval from 0 to 1 on the diagram represents the unit of measure for the quantity.

A rate of change expressed as a percent. The set of possible values of a random variable with a probability assigned to each. See Table 4 in this Glossary. See Table 5 in this Glossary. A probability model is used to assign probabilities to outcomes of a chance process by examining the nature of the process.

The set of all outcomes is called the sample space, and their probabilities sum to 1. An assignment of a numerical value to each outcome in a sample space. A quotient of two polynomials with a non-zero denominator. The rational numbers include the integers. A polygon all angles of which are right angles. Rigid motions are here assumed to preserve distances and angle measures.

The decimal form of a rational number. In a probability model for a random process, a list of the individual outcomes that are to be considered. A graph in the coordinate plane representing a set of bivariate data. For example, the heights and weights of a group of people could be displayed on a scatter plot. A rigid motion followed by a dilation. A drawing that looks like a segment of tape, used to illustrate number relationships. Also known as a strip diagram, bar model, fraction strip, or length model.