Addition by Partitioning worksheet for practicing addition through tens and units partitioning.

Let's solve this "Addition by Partitioning (A)" worksheet step-by-step. The goal is to break numbers into tens and units, add the tens separately, then the units, and finally combine them for the final answer.

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🔹 Part 1: Partition the numbers into tens and units

We need to split each number into its tens and units (ones).

| Number | Tens | Units |
|--------|------|-------|
| 28 | 2 | 8 |
| 12 | 1 | 2 |
| 63 | 6 | 3 |
| 90 | 9 | 0 |

✔ So:
- 28 → 2 tens, 8 units
- 12 → 1 ten, 2 units
- 63 → 6 tens, 3 units
- 90 → 9 tens, 0 units

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🔹 Part 2: Addition by Partitioning

We'll now solve each addition problem by partitioning both numbers into tens and units, adding tens together, units together, and then combining.

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#### ✔ 1. 13 + 25

- Partition:
- 13 = 10 + 3
- 25 = 20 + 5

- Add the Tens: 10 + 20 = 30
- Add the Units: 3 + 5 = 8
- Final Answer: 30 + 8 = 38

| Question | Add the Tens | Add the Units | Final Answer |
|---------|--------------|---------------|--------------|
| 13 + 25 | 10 + 20 = 30 | 3 + 5 = 8 | 30 + 8 = 38 |

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#### ✔ 2. 36 + 12

- 36 = 30 + 6
- 12 = 10 + 2

- Tens: 30 + 10 = 40
- Units: 6 + 2 = 8
- Final: 40 + 8 = 48

| 36 + 12 | 30 + 10 = 40 | 6 + 2 = 8 | 40 + 8 = 48 |

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#### ✔ 3. 51 + 18

- 51 = 50 + 1
- 18 = 10 + 8

- Tens: 50 + 10 = 60
- Units: 1 + 8 = 9
- Final: 60 + 9 = 69

| 51 + 18 | 50 + 10 = 60 | 1 + 8 = 9 | 60 + 9 = 69 |

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#### ✔ 4. 14 + 43

- 14 = 10 + 4
- 43 = 40 + 3

- Tens: 10 + 40 = 50
- Units: 4 + 3 = 7
- Final: 50 + 7 = 57

| 14 + 43 | 10 + 40 = 50 | 4 + 3 = 7 | 50 + 7 = 57 |

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#### ✔ 5. 22 + 32

- 22 = 20 + 2
- 32 = 30 + 2

- Tens: 20 + 30 = 50
- Units: 2 + 2 = 4
- Final: 50 + 4 = 54

| 22 + 32 | 20 + 30 = 50 | 2 + 2 = 4 | 50 + 4 = 54 |

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#### ✔ 6. 77 + 11

- 77 = 70 + 7
- 11 = 10 + 1

- Tens: 70 + 10 = 80
- Units: 7 + 1 = 8
- Final: 80 + 8 = 88

| 77 + 11 | 70 + 10 = 80 | 7 + 1 = 8 | 80 + 8 = 88 |

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#### ✔ 7. 42 + 25

- 42 = 40 + 2
- 25 = 20 + 5

- Tens: 40 + 20 = 60
- Units: 2 + 5 = 7
- Final: 60 + 7 = 67

| 42 + 25 | 40 + 20 = 60 | 2 + 5 = 7 | 60 + 7 = 67 |

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#### ✔ 8. 51 + 21

- 51 = 50 + 1
- 21 = 20 + 1

- Tens: 50 + 20 = 70
- Units: 1 + 1 = 2
- Final: 70 + 2 = 72

| 51 + 21 | 50 + 20 = 70 | 1 + 1 = 2 | 70 + 2 = 72 |

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#### ✔ 9. 35 + 44

- 35 = 30 + 5
- 44 = 40 + 4

- Tens: 30 + 40 = 70
- Units: 5 + 4 = 9
- Final: 70 + 9 = 79

| 35 + 44 | 30 + 40 = 70 | 5 + 4 = 9 | 70 + 9 = 79 |

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✔ Final Completed Table:

| Question | Add the Tens | Add the Units | Final Answer |
|---------|--------------|---------------|--------------|
| 13 + 25 | 10 + 20 = 30 | 3 + 5 = 8 | 30 + 8 = 38 |
| 36 + 12 | 30 + 10 = 40 | 6 + 2 = 8 | 40 + 8 = 48 |
| 51 + 18 | 50 + 10 = 60 | 1 + 8 = 9 | 60 + 9 = 69 |
| 14 + 43 | 10 + 40 = 50 | 4 + 3 = 7 | 50 + 7 = 57 |
| 22 + 32 | 20 + 30 = 50 | 2 + 2 = 4 | 50 + 4 = 54 |
| 77 + 11 | 70 + 10 = 80 | 7 + 1 = 8 | 80 + 8 = 88 |
| 42 + 25 | 40 + 20 = 60 | 2 + 5 = 7 | 60 + 7 = 67 |
| 51 + 21 | 50 + 20 = 70 | 1 + 1 = 2 | 70 + 2 = 72 |
| 35 + 44 | 30 + 40 = 70 | 5 + 4 = 9 | 70 + 9 = 79 |

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✔ Summary of Answers:

- Partitioned numbers:
- 28 → 2 tens, 8 units
- 12 → 1 ten, 2 units
- 63 → 6 tens, 3 units
- 90 → 9 tens, 0 units

- Sums:
- 13 + 25 = 38
- 36 + 12 = 48
- 51 + 18 = 69
- 14 + 43 = 57
- 22 + 32 = 54
- 77 + 11 = 88
- 42 + 25 = 67
- 51 + 21 = 72
- 35 + 44 = 79

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🎯 Explanation of Method: Addition by Partitioning

This method helps students understand place value by breaking numbers into tens and units before adding. It reinforces mental math and number sense.

For example:
51 + 18
→ Break into: (50 + 1) + (10 + 8)
→ Add tens: 50 + 10 = 60
→ Add units: 1 + 8 = 9
→ Combine: 60 + 9 = 69

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✔ Your Score: All 9 questions correct → Full score! 😊

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