Unit 2
Glossary
Grade 7
constant of proportionality
In a proportional relationship, the values for one quantity are each multiplied by the same number to get the values for the other quantity. This number is called the constant of proportionality.
In this example, the constant of proportionality is 3.
coordinate plane
The coordinate plane is one way to represent pairs of numbers. The plane is made of a horizontal number line and a vertical number line that cross at 0.
Pairs of numbers can be used to describe the location of a point in the coordinate plane.
Point
From an earlier course.
equivalent ratios
Two ratios are equivalent if each of the numbers in the first ratio can be multiplied by the same factor to get the numbers in the second ratio. For example,
A recipe for lemonade says to use 8 cups of water and 6 lemons. If 4 cups of water and 3 lemons are used, it will make half as much lemonade. Both recipes taste the same, because
| cups of water | number of lemons |
|---|---|
| 8 | 6 |
| 4 | 3 |
From an earlier course.
origin
The origin is the point
proportional relationship
In a proportional relationship, the values for one quantity are each multiplied by the same number to get the values for the other quantity.
This table shows a proportional relationship between
| 2 | 8 |
| 3 | 12 |
| 5 | 20 |
| 10 | 40 |