## On the Subject of Math 'em

Don't lose your brain in the shuffle.

On this module is a board with 16 tiles arranged into four rows.

Each tile can be one of four colours: White, Bronze, Silver, and Gold and one of three types: Constant, Variable, and Operator.

- Substitute in the values of each variable and read the tiles from left to right, top to bottom, to form a mathematical equation.
- Concatenate the digits of the tiles between each pair of operators to form a sequence of numbers.
- Sequentially apply each operator to each pair of numbers in reading order, taking the output of the previous operation as an input of the next, until left with a single number.
- If two or more operator tiles appear consecutively, the first and last of them form a
*Combined Operator.* - If the first tile is an operator, apply it to the first and last numbers of the sequence.
- If the last tile is an operator, apply it to the result of the previous operation and the first number of the sequence.

- If two or more operator tiles appear consecutively, the first and last of them form a
- Enter the output of the last operator into the keypad and submit it.
- Pressing the back key will remove the last entered digit.
- If the final value exceeds 99999999, enter only its last eight digits.

If the submission is correct, the hatch will open, revealing a button. Pressing this button will flip over the tiles and shuffle them five times. Each shuffle is one of the following:

- Swapping two rows/columns of tiles.
- Shifting a row/column one space.
- Cycling four tiles at the corners of a rectangle.

Once all five shuffles are complete, repeat the steps above, this time with the shuffled grid of tiles.

- Variables that are dependent on the position of tiles on the board are updated according to their new arrangement.
- Variables that are dependent on time are updated according to the time that the last shuffle was completed.

If an incorrect value is submitted at this stage, the board will reset and a new sequence of shuffles will begin once the button is pressed.