Well, first you would want to turn 1 1/10 and 1 7/8 into improper fractions. This would result in 11/10 and 15/8.
Next you want to find the smallest common denominator:
11/10 (4/4) = 44/40
15/8 (5/5) = 75/40
You would then subtract:
75/40 - 44/40 = 31/40
The number 31/40 would be the amount of food you aren't giving the dog per day (are cutting back on). Now you jut have to find out how many days are in the month to get your final answer.
