Question

if I buy an 8 foot piece of lumber & I needed 100 inches of lumber is that enough lumber that I bought

Answer 1

So first convert 8 feet to inches. Multiply 8×12. You get 96 inches. 96 is not 100. You need more.

Answer 2

1 foot = 12 inches


1 foot x 8 = 12 inches x 8
8 feet =  96 inches

4 inches less than the amount of lumber needed