To find out how many sour fruit chews Keenan can buy, you can divide the total amount of money he has by the price of each sour fruit chew.
Keenan has $3.15 and each sour fruit chew costs $0.07.
Here's the calculation:
\[ \text{Number of sour fruit chews} = \frac{3.15}{0.07} \]
Now, let's do the division:
\[ 3.15 \div 0.07 = 45 \]
Keenan can buy 45 sour fruit chews.