This video shows a Brainiac brain that knows how to play Sudoku. It has 3,600 neurons and 78,732 synapses. The user interface has been color-coded to indicate neurons firing at high frequency in orange, at medium frequency in green, at low frequency in blue, and neurons that are not firing in black. The white numbers were already provided as clues in this Sudoku puzzle, and the yellow numbers are guesses by the brain as it figures out the solution.