1. Proportional Relationships
Digits 2.1

3. How to find a proportion:

4. Are these proportions? a.) b.) c.)

5. Solve each proportion for the variable.
d.) e.) f.)

6. Proportion Word Problems
1.) If 3 volumes of Jennifer’s encyclopedia takes up 4 inches of space on her shelf, how much space will she need for all 26 volumes? 2.) John filled his new radiator with 6 pints of coolant, which is the 10 inch mark. How many pints of coolant would be needed to fill the radiator to the 25 inch level?

7. Race to Find the Proportion
a.) 10, 6, 30, 18 b.) 4, 6, 10, 15 c.) 12, 21, 7, 4

8. There are two ways you can determine if a table shows a proportional relationship:
1.) Find unit rate for each ratio. Are they the same? 2.) Set two ratios equal to each other, mark out one number, cross multiply the two corner numbers, then divide by the 3rd number. Did you get the 4th number? If so, the ratios are proportional.

9. Does this table show a proportional relationship?
Gallons of red paint per
each gallon of blue paint.
2 3 = .6 1
4 6 = .6 1
20 30 = .6 1
40 60 = .6 1

10. Does this table show a proportional relationship?
2 3 = 4 6
(4 ×3 ) ÷6

11. Perimeter Is the relationship between the
side length and the perimeter of
a square a proportional
relationship? How do you know?

12. Watch the video on 2-1 Part 2

13. Always put y on top and x on the bottom!

16. This is not a proportional relationship…