Solve the grid. Then solve the grid again.

enter image description here

The answer can be one or two letters long.


2 Answers 2


Building off of @dvx2718’s answer below,

I started by trying to connect the sequence they got:
to digits of pi. I noticed that 1573 and 49479 are both backwards excerpts from pi (within the first hundred digits) but couldn’t find any other matches.

At that point, I remembered Jujustum’s hint about the solve path. I started by looking at the solution one row at a time, and realized that the filled-in numbers were placed in the same positions as the same digits in the decimal portion of pi. Below is the grid filled in with the missing digits, though it should be noted that there is an error in the penultimate cell.

Nine by nine, sudoku style grid containing the first eighty-one decimal digits of pi

Thus, as per dvx2718, the solution would seem to be

π / pi.

  • $\begingroup$ You got it, well done! (and there is indeed a mistake in the penultimate cell, sorry! I must have forgot one of the two 9s) $\endgroup$
    – Jujustum
    Commented Jun 19 at 11:24
  • $\begingroup$ So that's the meaning of "solving the grid again"! Awesome work! $\endgroup$
    – dvx2718
    Commented Jun 19 at 13:51

Speculative answer

I firmly believe this is the answer but I cannot prove it because a key piece is missing, yet everything else lines up. If I shouldn't be posting a speculative answer like this please let me know as I'm new to the site.

The answer is:

In one letter: π, or in two letters: pi

The reasoning:

First, I solved the sudoku. enter image description here

Then, I note that there are exactly 32 cells to fill to solve this sudoku, and the word circle in the title makes me think of pi. Checking the first 32 digits of pi, we get 3.1415926535897932384626433832795, and the 33rd digit is 0. Since 0 cannot show up in sudoku, we see that from the beginning of pi, exactly 32 digits are usable in sudoku before we reach the first 0. Also, pi can be written using both a single letter π or two letters pi.

Here's the problem though:

I cannot find the relation between the solution to the sudoku and pi, other than the 32 digits thing. If we take the digits of the solution to the sudoku, that's 41965342862315732487264947952916, compare that with 3.1415926535897932384626433832795, the digits do not match.

  • 1
    $\begingroup$ The final result might be right… but I feel like you solved the grid only once! It’ll make more sense once you find the correct path to the answer. Also, speculative/partial answers are fine :) $\endgroup$
    – Jujustum
    Commented Jun 18 at 18:25
  • $\begingroup$ +1 looks like a great start, just to go further with the final point - if you run frequency analysis on the pi digits and the sudoku digits, the distributions don't match either, so the next step isn't for example setting all the 4s as 3s or something, a new set of numbers needs to be found somehow.... $\endgroup$ Commented Jun 18 at 19:11

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