Ratios & Proportional Relationships · Grade 7 · 7.RP.A.2.a
Roots of Reason
rootsofreason.org
Stuck? Scan for the anchor chart
Proportional or Not?
Name
Date
Correct / 8
1
Test the Table
- divide y by x on every row and write each quotient in the dashed cell. If any quotient differs, it is not proportional.
1.
| x | 2 | 5 | 8 |
| y | 5 | 12.5 | 20 |
| y ÷ x |
ProportionalNot
If it is proportional, k =
2.
| x | 1 | 2 | 3 |
| y | 5 | 7 | 9 |
| y ÷ x |
ProportionalNot
If it is proportional, k =
3.
| x | 2 | 4 | 6 | 8 | 10 |
| y | 3 | 6 | 9 | 12 | 15 |
| y ÷ x |
ProportionalNot
If it is proportional, k =
Ratios & Proportional Relationships · Grade 7 · 7.RP.A.2.a
Roots of Reason
rootsofreason.org
2
Test the Graph
- straight AND through the origin. If you cannot see the origin, test points instead.
4.
ProportionalNot
because
5.
ProportionalNot
because
6. origin off screen
ProportionalNot
because
3
In Context
- check: does zero of one mean zero of the other?
7. A climbing gym charges $12 to join, then $6 per visit. Is the total cost proportional to the number of visits?
ProportionalNot
How do you know?
8. Tomatoes cost $2.50 per pound, any amount. Is the total cost proportional to the number of pounds?
ProportionalNot
How do you know?
Ratios & Proportional Relationships · Grade 7 · 7.RP.A.2.a
Roots of Reason
rootsofreason.org
Proportional or Not?
1Test the Table
1.
| x | 2 | 5 | 8 |
| y | 5 | 12.5 | 20 |
| y ÷ x | 2.5 | 2.5 | 2.5 |
ProportionalNot
If it is proportional, k = 2.5
2.
| x | 1 | 2 | 3 |
| y | 5 | 7 | 9 |
| y ÷ x | 5 | 3.5 | 3 |
ProportionalNot
three different quotients. This is y = 2x + 3 in disguise
3.
| x | 2 | 4 | 6 | 8 | 10 |
| y | 3 | 6 | 9 | 12 | 15 |
| y ÷ x | 1.5 | 1.5 | 1.5 | 1.5 | 1.5 |
ProportionalNot
If it is proportional, k = 1.5
Ratios & Proportional Relationships · Grade 7 · 7.RP.A.2.a
Roots of Reason
rootsofreason.org
2Test the Graph
4. Proportional
because it is straight and it passes through (0, 0)
5. Not
because it is straight but starts above zero. Linear is not enough
6. Proportional
because 10÷4 = 15÷6 = 20÷8 = 2.5. The quotient test works even when the origin is off screen
3In Context
7. A climbing gym charges $12 to join, then $6 per visit.
Not
Zero visits still costs $12, so it is not proportional. Cost ÷ visits keeps changing: 18, 12, 10 . . .
8. Tomatoes cost $2.50 per pound, any amount.
Proportional
Zero pounds costs zero, and every pound adds the same $2.50. Cost ÷ pounds is always 2.5.