To determine the number of ounces of the chocolate cereal that you have eaten, the operation that needs to be performed is simply the multiplication of the initial number of ounce in the box of cereal and the decimal equivalent of the given percentage. If we let n be the answer,
n = (13 oz)(0.45)
Simplifying, this will give us the answer which is equal to 5.85 oz.
Answer: 5.85 oz.