Interpreting Rates
Student Summary
Suppose a farm lets us pick 2 pounds of blueberries for 5 dollars. We can say:
- We get 52 pound of blueberries per dollar.
- The blueberries cost 25 or 221dollars per pound.
The “price per pound of blueberries” and the “weight of blueberries per dollar” are the two unit rates describing this situation.
| weight of blueberries (pounds) |
price (dollars) |
|---|---|
| 2 | 5 |
| 1 | 25 |
| 52 | 1 |
A unit rate tells us how much of one quantity for 1 of the other quantity. Each of these numbers is useful in the right situation.
If we want to find out how much 8 pounds of blueberries will cost, it helps to know how much 1 pound of blueberries will cost.
| weight of blueberries (pounds) |
price (dollars) |
|---|---|
| 1 | 25 |
| 8 | 8⋅25 |
If we want to find out how many pounds we can buy for 10 dollars, it helps to know how many pounds we can buy for 1 dollar.
| weight of blueberries (pounds) |
price (dollars) |
|---|---|
| 52 | 1 |
| 10⋅52 | 10 |
Which unit rate is most useful depends on what question we want to answer, so be ready to find either one!
Visual / Anchor Chart
Standards
Addressing
6.RP.3.b
6.RP.A.3.b
6.RP.2
6.RP.3.b
6.RP.A.2
6.RP.A.3.b
Building Toward
6.RP.2
6.RP.A.2