Remember Volume of a cube is V=s to the power 3. So in exponential form the answer to your question is V=(14 ft) to the power 3. Or without units. V=(14) to the power 3.
You have -4,-3,-2, that is a 3 out of a total of 21 points or numbers on the number line. 3/21 is reduces to 1/7. 3 goes into 21 , 7 times. That is why it reduces to 1/7.