Question

James run 12 3/4 miles per day. He runs for 6 days the same amount of miles each day. How many miles does he run in all?

Answer 1

The answer is:  76.5 mi. (or, write as: 76 ½ mi. ). 
______________________
Explanation:

(12 ¾ mi / d) * 6 d =  ?  mi.
__________________________
 On the "left-hand side" of the equation, the units of "d" [for day(s)] cancel; and we are left with: 
_________________
12 ¾ mi * 6  =  ?  mi.   ;
__________________________
12 ¾ mi * 6  = (12 ¾ * 6) mi.  = 76.5 mi. (or, write as: 76 ½ mi. ). 

Answer 2

The number of miles run in all 6 days:  6 *  12     3/4

Change 12  3/4 to improper fraction =  (12*4 + 3) / 4 = (48 + 3) / 4 = 51 / 4

6 * 51/4

3 * 51/2 =   153/2 = 76.5

Miles run  in all = 76.5 Miles.

Hope this explains it.