Christy bought an 8 foot piece of lumber to trim a bookshelf. Altogether, she needs 100 inches of lumber for the trim. Did Christy buy enough lumber? Explain

To determine if she has enough, you need to convert feet to inches so you are comparing apples to apples. 1 foot is equal to 12 inches. So 8 feet is 96 inches (8 x 12). So is 96 inches enough for a 100 inch trim? No, sorry Christie!

There are 12 inches in a foot. So using the information you gave me and assuming there is no depth or width, only one measurement, she bought 96 inches of lumber, so no, she did not buy enough