60 − 30 O 3 = 50
(50 O 5) O 9 =5
70 + 28 O 7 = 74
56 O 8 * 7 = 49
8 O 6 + 52 = 100
63 O (13 − 6) = 9
84 O 14 = 98
90 O 10 = 9
8 O 10 = 80
60 − 30 : 3 = 50
(50 − 5) : 9 =5
70 + 28 : 7 = 74
56 : 8 * 7 = 49
8 * 6 + 52 = 100
63 : (13 − 6) = 9
84 + 14 = 98
90 : 10 = 9
8 * 10 = 80