The numbers follow a clockwise spiral path starting from the top-left square (6) and ending in the center (?). As you move along the spiral, the amount added to each number decreases by 1 each time:
Top-left to Top-middle: 6 + 9 = 15
Top-middle to Top-right: 15 + 8 = 23
Top-right to Middle-right: 23 + 7 = 30
Middle-right to Bottom-right: 30 + 6 = 36
Bottom-right to Bottom-middle: 36 + 5 = 41
Bottom-middle to Bottom-left: 41 + 4 = 45
Bottom-left to Middle-left: 45 + 3 = 48
Middle-left to Center: 48 + 2 = 50
