Ben1234:
Since gravity is always constant I have to subtract that out of the values. So at rest when it said g=1 then subtract 1 *9.8m/s^2 = 0 and when it is free falling with a reading of 0 then subtract 1 * 9.8m/s^2 = -9.8m/s^2
Technically the force of Earth's gravity is not constant from place to place and it can even slowly vary a bit over time. However, for your purposes this is should be good enough. 