1
Fill in the missing number. The cross follows: left × center right, and top × center bottom. =
2
Fill in the missing number. The cross follows: left + center right, and top + center bottom. =
3
Fill in the missing number. The cross follows: left - center right, and top - center bottom. =
4
Fill in the missing number. The cross follows: left + center right, and top + center bottom. =
5
Fill in the missing number. The cross follows: left + center right, and top + center bottom. =
6
Fill in the missing number. The cross follows: left - center right, and top - center bottom. =