write as 21/8 * 11/4
mulptiply 21/8 by 125 to get 2625/1000
multiply 11/4 by 250 to get 2750/1000
2625/1000 becomes 2.625
2750/1000 becomes 2.75
multiply to get 2.625*2.75=7.21875
(i know there is an easier way but i cant think of it off the top of my head)
