Convert rates and units in several steps
Grade 9 Math Worksheet - Building Confidence

Circle the best answer.
A pool holds 200 liters and fills at 90 liters per hour. Ren writes L for the liters after m minutes. Which equation is right?
- L = 200 + 90m
- L = 200 + 1.5m
- L = 200 + 5,400m
- L = 1.5m
A taxi charges $3 plus $1.80 per mile. Milo writes C for the cost of a ride of k kilometers (1 mile = 1.6 km). Which equation is right?
- C = 3 + 1.8k
- C = 1.125k
- C = 3 + 1.125k
- C = 3 + 2.88k
A plant is 12 cm tall and grows 2.1 cm per day. Kira writes H for the height after w weeks. Which equation is right?
- H = 14.7w
- H = 12 + 2.1w
- H = 12 + 0.3w
- H = 12 + 14.7w
A hose delivers 1,500 liters per hour. Zee wants the liters per minute. Which expression gives it?
- 1,500 × 60
- 60 ÷ 1,500
- 1,500 ÷ 60
- 1,500 + 60
A printer uses 2 cartridges per 1,500 pages, and each cartridge costs $18. Bo wants the dollars per page. Which expression gives it?
- 1,500 ÷ (2 × 18)
- (2 + 18) ÷ 1,500
- 2 × 18 ÷ 1,500
- 2 × 18 × 1,500
Luz burns 420 calories per hour while walking 6 kilometers per hour. Which expression gives the calories per kilometer?
- 420 ÷ 6
- 420 × 6
- 6 ÷ 420
- 420 + 6
The cost C in dollars of k kilowatt-hours is C = 0.08k + 5. Esme asks: what does 0.08 tell us?
- The total cost for any amount of electricity is $0.08.
- Each extra kilowatt-hour adds $0.08 to the cost.
- The cost is $0.08 when no electricity is used.
- Each extra dollar of cost uses 0.08 kilowatt-hours.
The height H in cm of a plant after d days is H = 12 + 2.1d. Jun asks: what does 2.1 tell us?
- The plant grows 2.1 cm every day.
- The plant is 2.1 cm tall at the start.
- Each centimeter of growth takes 2.1 days.
- The plant is 2.1 cm tall at every age.
A rider's distance D in km after t hours is D = 18t + 4. Noah asks: what does 18 tell us?
- The rider starts 18 km from the start line.
- Each kilometer takes the rider 18 hours.
- The rider covers 18 km each hour.
- The rider covers 18 km in total.
A pool's volume V in liters after m minutes of draining is V = 900 - 45m. Ari asks: what does 45 tell us?
- The pool starts with 45 liters.
- The pool loses 45 liters each minute.
- The pool loses 45 liters in total.
- Each liter drained takes 45 minutes.