A recipe for stir fry calls for 8 cups of rice for every 6 cups of veggies. Suppose a restaurant is making a large batch of stir fry using 15 cups of veggies. How much rice would they need?
Start by labeling the double number line with the cups of veggies and cups of rice that the recipe calls for.
Veggies (cups)
0
Rice (cups)
0
Excellent!
To find how many cups of rice they’d need for 15 cups of veggies, it can be helpful to first find the unit rate, or the amount of rice needed for 1 cup of veggies. Partition the number line to find the number of cups of rice needed for every 1 cup of veggies.
Veggies (cups)
0
6
Rice (cups)
0
8
Good work!
Label the bottom number line to find the number of cups of rice the restaurant would need for 1 cup of veggies.
Veggies (cups)
0
1
2
3
4
5
6
Rice (cups)
0
8
Next, find the unit rate by dividing the amount of rice by the amount of veggies: 8/6 = 1.33 cups of rice for every 1 cup of veggies.
Now, use this unit rate to find how much rice is needed for 15 cups of veggies: 15 (cups of veggies) x 1.33 (cups of rice per cup of veggies) = 19.95 or approximately 20 cups of rice.
Therefore, the restaurant would need approximately 20 cups of rice to make stir fry using 15 cups of veggies.