All you'd have to do is find a common denominator, which would be 24 (because both 8 and 6 go into it). So you'd multiply both 3 and 8 by 3 to get 9/24, and both 1 and 6 by 4 to get 4/24. Then you add 9/24 to 4/24 to get 13/24. Then you just get the left over fraction, which is 7/24. That's the allowance she spent on other items. I hope this helps!
