Board feet is a measurement of lumber volume. a board foot is equal to 144 in3 of wood. about how many board feet is a piece of lumber that measures 2 in. by 8 in. by 12 ft?

This is the concept of volumes of solid materials, the volume of lumber is given by:
volume=length*width*height
Volume=2*8*12=192in^3
The number of times a board whose volume is 144 in^3 would fit into the lumber will be given by:
[volume of lumber]/[volume of board]
=192/144
=1 1/3=4/3 times