TEAS Math key terms

A whole number that can be positive, negative, or zero, with no fractional or decimal part. Examples include -7, 0, and 12; numbers such as 3.5 or two-thirds are not integers.

Any number that can be written as a fraction with integers on top and a nonzero integer on the bottom. Its decimal form either stops or repeats, as in 0.25 or 0.333 repeating.

A number that cannot be written as a simple fraction of two integers. Its decimal form continues forever without repeating, as happens with pi and with the square root of 2.

The distance of a number from zero on a number line, written with two vertical bars around the number. Because distance is never negative, the absolute value of -6 is 6.

The top number of a fraction. It tells how many equal parts of the whole are being counted or described, as in three-eighths, where 3 is the top number.

The bottom number of a fraction. It names how many equal-sized parts make up one whole, and it can never be zero because division by zero is undefined.

Different fractions that name the same amount, such as one-half and four-eighths. Multiplying or dividing the top and bottom by the same nonzero number produces them.

The smallest number that every denominator in a group of fractions divides into evenly. It is used to rewrite fractions so they can be added or subtracted.

A number made of a whole number and a proper fraction written together, such as two and one-third. It can be rewritten as an improper fraction before multiplying or dividing.

A fraction whose numerator is equal to or larger than its denominator, such as seven-fourths. It represents one or more wholes and can be rewritten as a mixed number or decimal.

The value a digit has because of its position inside a number. In 4,052 the 4 means four thousands, the 5 means five tens, and moving one place left multiplies value by ten.

A way of comparing a number to 100, where the symbol means per hundred. For example, 45% equals 45 out of 100, or 0.45 written as a decimal.

A comparison of two quantities by division, often written as a fraction, with a colon, or with the word to. A ratio of 3 to 4 may be written 3:4 or three-fourths.

An equation stating that two ratios are equal, such as two-fifths equals six-fifteenths. Cross-multiplying turns a proportion into an equation you can solve for the missing value.

A rate in which the second quantity is exactly one unit, found by dividing. Traveling 150 miles in 3 hours gives a unit rate of 50 miles per hour.

The fixed number relating two quantities that grow at a steady ratio, usually written as k. In the equation y equals k times x, it equals y divided by x for every pair of values.

A letter or symbol that stands for an unknown or changing value in an expression or equation. In 5x plus 2, the letter x is the variable.

The number multiplied by a variable in an algebraic term. In 7y the coefficient is 7, and a term such as x with no visible number has a coefficient of 1.

A combination of numbers, variables, and operation signs with no equals sign, such as 3x minus 8. It can be simplified or evaluated for a given value but it cannot be solved.

A mathematical sentence stating that two expressions have the same value, shown with an equals sign. Solving it means finding the value or values of the variable that make the statement true.

An equation whose graph is a straight line and in which no variable is raised to a power above one. It is often written in the form y equals mx plus b.

A statement comparing two expressions that are not necessarily equal, using symbols such as less than, greater than, less than or equal to, or greater than or equal to. Its solution is a range of values.

The agreed sequence for evaluating an expression: grouping symbols first, then exponents, then multiplication and division from left to right, then addition and subtraction from left to right.

A small raised number that shows how many times the base is used as a factor. In three to the fourth power, the base 3 is multiplied by itself four times.

A number that gives the original value when multiplied by itself. The square root of 49 is 7, because 7 times 7 equals 49.

A rule allowing you to multiply a number by a sum or difference by multiplying each part separately, so a times the sum of b and c equals ab plus ac. It is used to expand or factor expressions.

A measure of how steep a line is, calculated as the vertical change divided by the horizontal change between two points on the line, often called rise over run.

The point where a line crosses the vertical axis, written as zero comma b. In the equation y equals mx plus b, the letter b gives this value.

A rule that pairs every input value with exactly one output value. On a graph it passes the vertical line test, since no vertical line touches the graph twice.

The average of a data set, found by adding all the values and dividing by how many values there are. A single very large value can pull the mean upward.

The middle value of a data set listed in order from least to greatest. When the set has an even number of values, the median is the mean of the two middle values.

The value that appears most often in a data set. A data set may have one mode, several modes, or no mode when every value appears the same number of times.

The difference between the largest and the smallest values in a data set, found by subtracting. It describes how spread out the data are but ignores the values in between.

A number from 0 to 1 that describes how likely an event is, often written as the count of favorable outcomes divided by the count of all possible outcomes.

The amount of flat surface a two-dimensional shape covers, measured in square units. A rectangle's area equals its length multiplied by its width.

The total distance around the outside of a two-dimensional shape, found by adding the lengths of all its sides. It is measured in linear units such as inches or meters.

The amount of space a three-dimensional solid occupies, measured in cubic units. The volume of a rectangular box equals length times width times height.

The distance around the outer edge of a circle, calculated as pi times the diameter or as two times pi times the radius.

A rule for right triangles saying the squares of the two shorter sides add up to the square of the longest side, written a squared plus b squared equals c squared.

A way of writing very large or very small numbers as a value between 1 and 10 multiplied by a power of 10, such as 4.2 times 10 to the third.