To find out how much pink paint Larry had left, we subtract the amount of paint he used from the total amount he had:

1. Total amount of paint = 18 cans
2. Paint used = 9 1/2 cans (which is equivalent to 9.5 cans)

Now subtract the amount used from the total:

$18 - 9.5 = 8.5 \, \text{cans}$

So, Larry had 8 1/2 cans of pink paint left.

Would you like a more detailed explanation or have other questions?

Here are some related questions for further exploration:

1. What is the fractional part of the paint used in the problem?
2. How can you convert mixed numbers into improper fractions and vice versa?
3. How would this problem change if Larry used a different number of cans?
4. What happens if you have more cans of paint than needed for a project?
5. How would you calculate how much paint is left if it were used in multiple smaller projects?

Tip: When working with fractions and decimals, always convert mixed numbers to improper fractions or decimals to simplify calculations.