linear ft to cubic ft

:? if i have a plank of timber 12 ft long by 9 inchs wide by 2 inches thick how do i find out how many cubic feet are in that plank?

First, convert to like terms. In this case, I would convert to feet. To do that, divide inches by 12 (inches):

9 / 12 = 0.75 feet
2 / 12 = 0.167 feet

Now, multiply all three together to obtain cubic feet:

12' * 0.75' * 0.167' = 1.50 cubic feet