The remainder:
8 3/8 - 2 1/2
8 3/8 = (8*8 + 3)/8 =(64 + 3)/8 = 67 / 8
2 1/2 = (2*2 + 1)/2 = (4 + 1)/2 = 5/2
8 3/8 - 2 1/2 = 67/8 - 5/2
67/8 - 5/2 = 67/8 - (5/2)*(4/4) = 67/8 - (5*4)/(2*4) = 67/8 - 20/8
= 67/8 - 20/8
= (67 - 20)/8
= 47/8
= 5 7/8
Remainder = 5 7/8 inches.
Hope this helped.