Where the correct digits are underlined.

The correct digits are underlined in the above example.

We see that the number of correct digits after the decimal point increases from 2 (for "x") to 5 and 10, illustrating the quadratic convergence.

It is notable for being rapidly convergent, with only 25 iterations producing 45 million correct digits of π.

If the correct digit was not guessed, the number was placed in the check and the check writer won that amount in cash.

Each iteration approximately doubles the number of correct digits.

Then p converges quartically to π; that is, each iteration approximately quadruples the number of correct digits.

In this case quickly means that for both methods, the number of correct digits in the answer doubles with each step.

When solving longer sums there are additional ways to find clues to locating the correct digits.

Players who matched the letter with the correct six digits would win the top prizes.