Front

8 + 5 = ?

Back

(8 + 2 = 10, then +3 more) → 13

Front

7 + 6 = ?

Back

(7 + 3 = 10, then +3 more) → 13

Front

9 + 4 = ?

Back

(9 + 1 = 10, then +3 more) → 13

Front

6 + 8 = ?

Back

(6 + 4 = 10, then +4 more) → 14

Front

5 + 7 = ?

Back

(5 + 5 = 10, then +2 more) → 12

Front

9 + 7 = ?

Back

(9 + 1 = 10, then +6 more) → 16

Front

8 + 9 = ?

Back

(8 + 2 = 10, then +7 more) → 17

Front

6 + 6 = ?

Back

(6 + 4 = 10, then +2 more) → 12

Front

7 + 8 = ?

Back

(7 + 3 = 10, then +5 more) → 15

Front

5 + 6 = ?

Back

(5 + 5 = 10, then +1 more) → 11