Grade 7 · Unit 1 · Lesson 7 · part 3 of 5
Two more rates
Two more.
Two more rates
Two more. Say the sense check out loud each time.
A soccer sprint
A player sprints 6 meters per second.
Seconds to minutes: a minute has 60 seconds, so 6 × 60 = 360 meters per minute. (Longer time, bigger number.)
Then minutes to hours and meters to kilometers: 360 × 60 = 21,600 meters per hour, and 21,600 ÷ 1,000 = 21.6 kilometers per hour. (Bigger unit, smaller number.)
A dripping faucet
A faucet drips 2 cups an hour.
Hours to days: a day has 24 hours, so 2 × 24 = 48 cups a day. (Longer time, bigger number.)
Cups to gallons: a gallon is 16 cups, so 48 ÷ 16 = 3 gallons a day. (Bigger unit, smaller number.)
- 1 mile = 5,280 feet
- 1 hour = 60 minutes; 1 minute = 60 seconds; 1 day = 24 hours
- 1 kilometer = 1,000 meters
- 1 gallon = 16 cups; 1 gallon = 4 quarts
- 1 foot = 12 inches; 1 yard = 3 feet
Notice what you are not doing: no long chains of fractions with units crossed out. One unit, one multiply or divide, one sense check. Then the next unit.