This machine adds together any two numbers up to 15 (in binary). Select the first number using the top left set of boxes by dropping a ball for each "1". Select the second number. Double click the equal sign. The sum in binary will be calculated in the boxes across the bottom. The white asterisk gives you a hint about the location of the black ball. Only certain numbers will "solve" the level, but try all the combinations for fun, or use this calculator the next time you need to add up your GM premium dues or pay off a Finnish judge.