Unit 1: Quantities and Modeling

constant

A value that does not change

Variable

A symbol used to represent a quantity that can change

Coefficient

A number is multiplied by a variable in an algebraic expression.

algebreic expression

A combination of variables, numbers, and at least one operation.

ratio

A comparison of two quantities by division

proportion

an equation that states that two ratios are equal

scale

the ratio of any length in a scale drawing or scale model to the corresponding actual length

scale drawing

a drawing that is the same shape as the object it represents

scale model

a model used to represent an object that is too large or too small to be built at the actual size

rate

A ratio that compares two quantities measured in different units

conversion factor

a ratio of equivalent measurements

numerical expression

An expression that contains only numbers and operations

equivalent expressions

Expressions with the same value

Literal Equations

equations that contain two or more variables and sometimes no numbers at all

compound statement

two or more statements joined by the word "and" or "or"

intersection

the point at which two lines or roads meet and cut across each other

union

combined region, of the simple inequality graphs

less than

Less than is used to compare two numbers when the first number is smaller than the second number.

less than or equal to

≤

more than

>

more than or equal to

greater than or equal to