Question

Brian bought a 15-pound bag of concrete. He spilled the bag into smaller bags that each holds 2 1/2 pounds. How many smaller bags did he fill?

Answer 1

Let's first convert 2 and 1/2 into an improper fraction, it will help later:
$2 \frac{1}{2} = \frac{2*2+1}{2} = \frac{5}{2}$

Now, just divide:
$\frac{15}{ \frac{5}{2} }$

Which is the same thing as:
$15 * \frac{2}{5}$

Which you can simplify to:
$\frac{30}{5} = 6$

So your answer will be 6 smaller bags.