How would i solve something like 15/3?

That is 15/3 which is 3 into 15 and your answer is 5

The division operator is a way of sharing objects into groups of the same size. A way of thinking of the problem is, "How many times can 3 repeat itself before reaching 15?". 
1 Time = 3
2 Times = 6
3 Times = 9
4 Times = 12
5 Times = 15 
Awesome! That means that five 3's can go into 15. So, 15/3 = 5. The more you practice, the easier it will get! 

Fran can park for 6 hours! he has $7.50. if the first hour is $2 7.50-2=5.50. each hour is another $1. 5.50-1=4.50 4.50-1=3.50 3.50-1=2.50 2.50-1=1.50 1.50-1=.50. he is left with .50