The Hamiltion family walked four over five of a mile in four over nine of an hour. What is their unit rate in miles per hour?

 

   The Hamiltion family walked four over five of a mile in four over nine of an hour.     

   What is their unit rate in miles per hour?     

 

   "miles per hour" = miles / hour    Remember, "per" always means "divided by".     

 

   (4/5) mile / (4/9) hour                  To divide by a fraction, invert its divisor and multiply.     

 

     4  mile                    4  hour              4  mile              9     

   ––––––– divided by –––––––    =    ––––––– times –––––––    =    36 / 20 mi/hr    =    1.8 mph     

     5                             9                       5                      4  hour     

   _.