ratios Vocabulary
JamWise Education TeamยทUpdated March 2026
The ratios strand is a core part of the K-8 math curriculum. It encompasses 24 vocabulary terms that students encounter as they progress from kindergarten through 8th grade. Each term builds on previous knowledge, creating a spiral of deepening understanding that prepares learners for increasingly complex concepts.
Understanding ratios vocabulary is essential for classroom discussions, assessments, and real-world application. Below you will find every term organized by grade level, so teachers and parents can quickly identify which words are appropriate for their students and explore definitions tailored to each developmental stage.
6th Grade
(8 terms)
Double number line diagram
A pair of parallel number lines with 0 lined up, used to show equivalent ratios between two quantities.
Equivalent ratios
Two ratios that describe the same relationship. If you multiply both numbers in a ratio by the same factor, you get an equivalent ratio.
Percent
Percent means 'per 100' or 'for each 100.' It is represented by the % symbol. 25% means 25 out of 100.
Ratio
A ratio compares two quantities using division. You can write it as 3 to 2, 3:2, or 3/2.
Speed
How fast something is moving, measured as distance divided by time. If you bike 12 miles in 2 hours, your speed is 6 miles per hour.
Tape diagram
A group of rectangles put together to represent a relationship between quantities. Tape diagrams help you see how quantities compare.
Unit price
The cost for one item or one unit of measure. If 6 apples cost $3, the unit price is $0.50 per apple.
Unit rate
A rate that tells how many of one quantity there are per one unit of another quantity. For example, 60 miles per 1 hour.
7th Grade
(19 terms)
Commission
Money earned as a percentage of sales. If a salesperson earns 5% commission on a $2,000 sale, they earn $100.
Constant of proportionality
The constant ratio between two proportional quantities. In y = kx, the value k is the constant of proportionality. It is also the unit rate.
Discount
A reduction in the original price of an item, usually expressed as a percent. A 20% discount on a $50 item saves you $10.
Markup
The amount a seller adds to the cost of an item to set the selling price. If a store buys a shirt for $15 and sells it for $25, the markup is $10.
Percent error
The difference between an estimated value and the actual value, expressed as a percent of the actual value.
Percentage decrease
The amount of decrease expressed as a percent of the original value. If a price goes from $50 to $40, the percentage decrease is 20%.
Percentage increase
The amount of increase expressed as a percent of the original value. If a price goes from $20 to $25, the percentage increase is 25%.
Proportion
An equation that states two ratios are equal. For example, 3/4 = 6/8 is a proportion.
Proportional relationship
A relationship between two quantities where the ratio stays constant. Its graph is a straight line that passes through the origin (0,0).
Ratio
A comparison of two quantities that shows how many times one value contains the other. Can be written as a:b, a/b, or a to b.
Scale
The ratio between measurements on a drawing or model and the actual measurements. A scale of 1:100 means 1 cm on the drawing equals 100 cm in real life.
Scale drawing
A drawing that represents a real object where all measurements are proportional. A map is a scale drawing of a larger area.
Scale factor
The ratio used to enlarge or reduce a figure. A scale factor of 2 means every length is doubled.
Scaled copy
A copy of a figure where every length is multiplied by the same scale factor. The shape stays the same but the size changes.
Simple interest
Money earned or paid on a principal amount, calculated using I = Prt, where P is principal, r is rate, and t is time.
Tape diagram
A visual model using rectangles to show how parts relate to a whole or to each other. Useful for solving ratio and percent problems.
Tax
An additional amount added to the price of goods or services, calculated as a percent of the cost. Sales tax is a common example.
Tip
An extra amount of money given for a service, usually calculated as a percent of the bill. A 15% tip on a $40 meal is $6.
Unit rate
A rate in which the second quantity is one unit. If 150 miles takes 3 hours, the unit rate is 50 miles per hour.