Lets convert the fraction first to ease the calculations: 2 5/8 = 16/8 + 5/8 = 21/8 so now we can operate easily, to calculate we need to multiply 21/8 by 2/3 that is because, if 1/3 is used then 2/3 are left over (1/3 + 2/3 = 1, the total), so we have: (2/3)(21/8) = (2*21)/(3*8) = 42/24 = 21/12 = 7/4 so 7/4 are left over
