Addition worksheet for practicing doubles plus 2 math problems.

Here are the solutions for the addition problems. I have calculated each sum carefully.

Column 1:
* $3 + 3 = 6$
* $9 + 9 = 18$
* $9 + 11 = 20$
* $8 + 10 = 18$
* $2 + 4 = 6$
* $7 + 8 = 15$
* $2 + 2 = 4$
* $3 + 5 = 8$
* $3 + 4 = 7$
* $9 + 10 = 19$
* $7 + 8 = 15$
* $5 + 5 = 10$
* $9 + 9 = 18$
* $4 + 5 = 9$

Column 2:
* $7 + 9 = 16$
* $1 + 1 = 2$
* $5 + 5 = 10$
* $4 + 4 = 8$
* $10 + 11 = 21$
* $7 + 7 = 14$
* $6 + 7 = 13$
* $1 + 2 = 3$
* $4 + 5 = 9$
* $5 + 6 = 11$
* $4 + 4 = 8$
* $6 + 8 = 14$
* $3 + 5 = 8$
* $7 + 8 = 15$

Column 3:
* $2 + 3 = 5$
* $10 + 10 = 20$
* $8 + 8 = 16$
* $4 + 6 = 10$
* $6 + 8 = 14$
* $6 + 6 = 12$
* $1 + 3 = 4$
* $8 + 9 = 17$
* $5 + 7 = 12$
* $10 + 12 = 22$
* $5 + 5 = 10$
* $7 + 7 = 14$
* $3 + 4 = 7$
* $9 + 11 = 20$

Final Answer:
Column 1: 6, 18, 20, 18, 6, 15, 4, 8, 7, 19, 15, 10, 18, 9
Column 2: 16, 2, 10, 8, 21, 14, 13, 3, 9, 11, 8, 14, 8, 15
Column 3: 5, 20, 16, 10, 14, 12, 4, 17, 12, 22, 10, 14, 7, 20