Let’s solve each addition problem step by step. We’ll add the numbers in each column from top to bottom.
---
First row:
1.
10
35
10
+12
→ 10 + 35 = 45; 45 + 10 = 55; 55 + 12 =
67
2.
10
11
24
+13
→ 10 + 11 = 21; 21 + 24 = 45; 45 + 13 =
58
3.
11
22
15
+21
→ 11 + 22 = 33; 33 + 15 = 48; 48 + 21 =
69
4.
27
21
10
+11
→ 27 + 21 = 48; 48 + 10 = 58; 58 + 11 =
69
---
Second row:
5.
16
32
10
+11
→ 16 + 32 = 48; 48 + 10 = 58; 58 + 11 =
69
6.
11
22
12
+24
→ 11 + 22 = 33; 33 + 12 = 45; 45 + 24 =
69
7.
10
10
22
+26
→ 10 + 10 = 20; 20 + 22 = 42; 42 + 26 =
68
8.
10
13
10
+36
→ 10 + 13 = 23; 23 + 10 = 33; 33 + 36 =
69
---
Third row:
9.
20
21
10
+18
→ 20 + 21 = 41; 41 + 10 = 51; 51 + 18 =
69
10.
10
17
11
+31
→ 10 + 17 = 27; 27 + 11 = 38; 38 + 31 =
69
11.
12
12
11
+34
→ 12 + 12 = 24; 24 + 11 = 35; 35 + 34 =
69
12.
18
21
10
+20
→ 18 + 21 = 39; 39 + 10 = 49; 49 + 20 =
69
---
Fourth row:
13.
10
33
12
+14
→ 10 + 33 = 43; 43 + 12 = 55; 55 + 14 =
69
14.
32
10
10
+17
→ 32 + 10 = 42; 42 + 10 = 52; 52 + 17 =
69
15.
12
16
20
+20
→ 12 + 16 = 28; 28 + 20 = 48; 48 + 20 =
68
16.
10
31
13
+12
→ 10 + 31 = 41; 41 + 13 = 54; 54 + 12 =
66
---
Now, let’s list all answers in order (left to right, top to bottom):
Row 1: 67, 58, 69, 69
Row 2: 69, 69, 68, 69
Row 3: 69, 69, 69, 69
Row 4: 69, 69, 68, 66
Double-checking a few that were not 69:
- Problem 1: 10+35+10+12 → 67
✔
- Problem 2: 10+11+24+13 → 58
✔
- Problem 7: 10+10+22+26 → 68
✔
- Problem 15: 12+16+20+20 → 68
✔
- Problem 16: 10+31+13+12 → 66
✔
All others are 69 — which makes sense since many combinations were designed to sum to 69.
Final Answer:
67, 58, 69, 69, 69, 69, 68, 69, 69, 69, 69, 69, 69, 69, 68, 66
Parent Tip: Review the logic above to help your child master the concept of adding whole numbers worksheet.
