Ratios, Rates and Proportions

Percent

A percent is a ratio whose second term is 100. Percent means parts per hundred. The word comes from the Latin phrase per centum, which means per hundred. In mathematics, we use the symbol % for percent.

Proportion

A proportion is two ratios that have been set equal to each other; a proportion is an equation that can be solved. When I say that a proportion is two ratios that are equal to each other, I mean this in the sense of two fractions being equal to each other.

Rate

A rate is a special ratio in which the two terms are in different units. For example, if a 12-ounce can of corn costs 69¢, the rate is 69¢ for 12 ounces. The first term of the ratio is measured in cents; the second term in ounces.

Ratio

A ratio is a statement of how two numbers compare. It is a comparison of the size of one number to the size of another number. All of the lines below are different ways of stating the same ratio.

Table

A table is a set of data arranged in rows and columns.

Expression

A variable is a symbol used to represent a number in an expression or an equation. The value of this number can change. An algebraic expression is a mathematical expression that consists of variables, numbers and operations. The value of this expression can change.

Ordered Pair

An ordered pair is a pair of numbers used to locate a point on a coordinate plane; the first number tells how far to move horizontally and the second number tells how far to move vertically.

Coordinate Plane

The plane determined by a horizontal number line, called the x-axis, and a vertical number line, called the y-axis, intersecting at a point called the origin. Each point in the coordinate plane can be specified by an ordered pair of numbers.

Verbal Description

Verbal description uses nonvisual language to convey the visual world. It can navigate a visitor through a museum, orient a listener to a work of art, or provide access to the visual aspects of a performance.

Unit Rate

When rates are expressed as a quantity of 1, such as 2 feet per second or 5 miles per hour, they are called unit rates. If you have a multiple-unit rate such as 120 students for every 3 buses, and want to find the single-unit rate, write a ratio equal to the multiple-unit rate with 1 as the second term.

Additive

characterized or produced by addition; cumulative: an additive process. 4. Mathematics. (of a function) having the property that the function of the union or sum of two quantities is equal to the sum of the functional values of each quantity; linear.

Qualitative

relating to, measuring, or measured by the quality of something rather than its quantity.

Quantitative

relating to, measuring, or measured by the quantity of something rather than its quality.

Multiplicative

subject to or of the nature of multiplication.

Graph

In a mathematician's terminology, a graph is a collection of points and lines connecting some (possibly empty) subset of them. The points of a graph are most commonly known as graph vertices, but may also be called "nodes" or simply "points."

Equation

In mathematics, an equation is an equality containing one or more variables. Solving the equation consists of determining which values of the variables make the equality true. In this situation, variables are also known as unknowns and the values which satisfy the equality are known as solutions.