**How To Play:** Use the left/right arrow keys to select one of the four cells, then up/down to add or subtract that number to the sum in the middle of the screen. Advance to the next level by making the sum equal to the target in the upper left corner. The multiplier at the top of the screen is also the number of tries per level; each time you add/subtract the multiplier decreases by one. Try to reach 1000!