1 + 2 = 3
1 + 4 = 3
16 + 4 = 11
4 + 4 = 7
5 + 4 = 6
5 + 2 = 10
6 + 2 = 10
2 + 2 = 7
8 + 10 = 5
4 + 10 = 4
5 + 10 = 4
3 + 10 = 5
81 + 7 = ?
Hint
$10 + 1 \ne 1 + 10$
Hint 2
The number four
What is the pattern? What is 81 + 7? How are the results calculated?