A car is traveling 75 miles per hour. How many miles does the car travel in one minute?

Question

Homework for 7th grade math

Answer 1

You are learning about the multiplicative identity (that is, 1).  We may multiply or divide any value by 1 and not change the value, but we may change the units.  For example,

             (2 yards)

             (2 yards) * 1

             (2 yards) * (3 feet / 1 yard)

             (6 feet)             [note: yards cancel out, leaving only feet]

 

Problem:

          75 miles per hour

          (75 miles)/(1 hour)

          ( (75 miles)/(1 hour) ) * ( (1 hour)/(60 minutes) )

          (75/60) miles/minute             [hours cancel out, leaving only miles/minute]

             1.25 miles/minute        [1.25 miles per minute]            

 

(p.s., for when you learn to drive, remember that 60 mph is 1 mile/minute)

Answer 2

Convert 75 miles/hour to miles/minute buy multiplying by 1hour/60minutes:

 

75 miles/hour * 1hour/60 minutes = 1.25 miles/minute

 

Now multiply the speed in miles/minute by one minute:

 

1.25 miles/minute * 1minute = 1.25 miles