How many servings of cereal in 450-gram box? I am helping my brother with his math again - I need a way to explain this to him! I am ages past this and don't have the time to find an explanation and figured that asking here would be quicker. The question is: A $450$-gram box of cereal gives the servings as $\frac{3}{4}$ of an ounce. How many servings are in the box? The answer book gives 24 servings as the answer, but does not explain why or how! Would someone care to explain it to me, briefly? Thanks a ton for _your_ time! What I have tried - $1$ ounce = $28.35$ grams I need to find $\frac{3}{4}$ of an ounce $=\frac{28.35}{4}=7.0875$ grams $=\frac{1}{4}$ ounce$\;*\;3=21.2625$ = $\frac{3}{4}$ ounce. Then this is where I get stuck.

$450$ grams is about a pound. (I think it's closer to $454$ grams.)

So doing the ratio gives

$$16 \text{ ounces} \times \frac{1 \text{ serving}}{3/4 \text{ ounce}} = 21 \text{ servings and change.}$$

I think you're right, and the answer key is wrong.