Simplify the following text for a Grade 9 native English-speaking person.
Original: The Fourier transform is also defined for such a function . As we increase the length of the interval on which we calculate the Fourier series , then the Fourier series coefficients begin to look like the Fourier transform and the sum of the Fourier series of Æ ' begins to look like the inverse Fourier transform .
Simplified: The Fast Fourier Transform is a way of calculating a Fourier transform much faster with a computer .