60 + 8 = 68
70 + 5 = 75
50 + 2 = 52
7 tens and 5 units
6 tens and 8 units
5 tens and 2 units
40 + 9 = 49
90 + 4 = 94
80 + 9 = 89
9 tens + 4 units
8 tens + 9 units
4 tens + 9 units
70 + 7 = 77
80 + 0 = 80
0 + 8 = 8
7 tens + 7 units
8 tens + 0 units
0 tens + 8 units