Let’s solve each addition problem step by step. We’ll go row by row, left to right.
First column:
9 + 0 = 9
(Adding zero doesn’t change the number.)
9 + 1 = 10
(One more than 9 is 10.)
9 + 2 = 11
(Start at 9, count up 2: 10, 11.)
9 + 3 = 12
(9 + 1 = 10, then +2 more = 12.)
9 + 4 = 13
(9 + 1 = 10, then +3 more = 13.)
9 + 5 = 14
(9 + 1 = 10, then +4 more = 14.)
9 + 6 = 15
(9 + 1 = 10, then +5 more = 15.)
9 + 7 = 16
(9 + 1 = 10, then +6 more = 16.)
9 + 8 = 17
(9 + 1 = 10, then +7 more = 17.)
9 + 9 = 18
(9 + 1 = 10, then +8 more = 18 — or think of it as double 9.)
Second column:
9 + 9 = 18
(Same as above — double 9.)
8 + 9 = 17
(Start with 8, add 9: 8 + 2 = 10, then +7 more = 17.)
7 + 9 = 16
(7 + 3 = 10, then +6 more = 16.)
6 + 9 = 15
(6 + 4 = 10, then +5 more = 15.)
5 + 9 = 14
(5 + 5 = 10, then +4 more = 14.)
4 + 9 = 13
(4 + 6 = 10, then +3 more = 13.)
3 + 9 = 12
(3 + 7 = 10, then +2 more = 12.)
2 + 9 = 11
(2 + 8 = 10, then +1 more = 11.)
1 + 9 = 10
(Just one less than 10? No — 1 + 9 makes exactly 10.)
0 + 9 = 9
(Zero plus any number is that number.)
Now let’s write all answers in order, matching the grid:
Left Column (top to bottom):
9, 10, 11, 12, 13, 14, 15, 16, 17, 18
Right Column (top to bottom):
18, 17, 16, 15, 14, 13, 12, 11, 10, 9
Final Answer:
Left Column: 9, 10, 11, 12, 13, 14, 15, 16, 17, 18
Right Column: 18, 17, 16, 15, 14, 13, 12, 11, 10, 9
Parent Tip: Review the logic above to help your child master the concept of adding 9 worksheet.
