So, initially 240
-212 
were empty:
this is :
12/4 is 4 so that's why i substituted it with 4.
now, later 27 1/3 were used so we add this tho the original empty space
= 
= 
which is the result!
this is :
12/4 is 4 so that's why i substituted it with 4.
now, later 27 1/3 were used so we add this tho the original empty space
which is the result!