Suzi works as a nanny. She can spend $40 a month on arts and crafts supplies. This month, Suzi spent $12 on specialty paper and $8 on felt. How much more can she spend this month on arts and crafts without having a negative balance?
Suzie can ONLY spend $40 and she spent $12 and another $8 dollars so first you have to add 12+8= 20 and she can only use $40 a month and so far this month to find out you would have to subtract what she has just used. So $40-$20 is $20 she can only use $20 left this month.
