Compare this quantity with the amount of wheat on the 56th square. You should have a function relating the number of the square to the amount of grain on that square. Having a variable as the exponent may be a new thing for you, and it causes somewhat surprising effects, as you may have seen in your calculations of the amount of wheat on the chessboard squares. 2 X is an exponential function. Exponential functions represent the kind of growth that happens when the amount of increase depends on how much is already there.
Population is an example.
The more people there are, the more babies they can make, and thus the more rapidly the population can change. Using values from the table below, if you put 2000 into the equation, you should get a result of nearly 6. Calculate the time intervals between the years you calculated, and write them in the left column.