Addition properties worksheet for practicing number facts and sum matching.

Problem Analysis:

The task involves understanding and applying the addition properties to solve for missing numbers and identifying addition facts that satisfy specific conditions. Let's break it down step by step.

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Step 1: Solve for the Missing Numbers

We are given several equations with a missing number represented by a box (□). We need to determine the value of the missing number in each case.

#### Equation 1: \( \boxed{6} + 0 = 0 + \boxed{6} = 6 \)
- The equation is symmetric, and any number added to 0 remains unchanged.
- Therefore, the missing number is \( 6 \).

#### Equation 2: \( \boxed{7} + 5 = 12 \)
- To find the missing number, we solve \( x + 5 = 12 \):
\[
x = 12 - 5 = 7
\]
- Therefore, the missing number is \( 7 \).

#### Equation 3: \( 11 + \boxed{0} = 11 \)
- Any number added to 0 remains unchanged.
- Therefore, the missing number is \( 0 \).

#### Equation 4: \( 6 + \boxed{6} = 12 \)
- To find the missing number, we solve \( 6 + x = 12 \):
\[
x = 12 - 6 = 6
\]
- Therefore, the missing number is \( 6 \).

#### Equation 5: \( 13 + \boxed{6} = 19 \)
- To find the missing number, we solve \( 13 + x = 19 \):
\[
x = 19 - 13 = 6
\]
- Therefore, the missing number is \( 6 \).

#### Equation 6: \( \boxed{0} + 3 = 3 \)
- Any number added to 0 remains unchanged.
- Therefore, the missing number is \( 0 \).

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Step 2: Identify Addition Facts with Specific Sums

We are asked to circle the addition facts that have specific sums. Let's identify them one by one.

#### Fact 1: Sum = 2 + 3 = 5
- We need to find an addition fact that equals 5.
- From the given options:
\[
1 + 5 = 6 \quad (\text{Not equal to 5})
\]
\[
4 + 2 = 6 \quad (\text{Not equal to 5})
\]
\[
8 + 5 = 13 \quad (\text{Not equal to 5})
\]
\[
6 + 2 = 8 \quad (\text{Not equal to 5})
\]
\[
7 + 4 = 11 \quad (\text{Not equal to 5})
\]
\[
9 + 9 = 18 \quad (\text{Not equal to 5})
\]
\[
1 + 6 = 7 \quad (\text{Not equal to 5})
\]
\[
2 + 4 = 6 \quad (\text{Not equal to 5})
\]
\[
5 + 9 = 14 \quad (\text{Not equal to 5})
\]
\[
2 + 6 = 8 \quad (\text{Not equal to 5})
\]

- None of the given facts equal 5. This might be an error in the problem statement or a misinterpretation. However, based on the provided options, there is no correct answer here.

#### Fact 2: Sum = 5 + 5 = 10
- We need to find an addition fact that equals 10.
- From the given options:
\[
1 + 5 = 6 \quad (\text{Not equal to 10})
\]
\[
4 + 2 = 6 \quad (\text{Not equal to 10})
\]
\[
8 + 5 = 13 \quad (\text{Not equal to 10})
\]
\[
6 + 2 = 8 \quad (\text{Not equal to 10})
\]
\[
7 + 4 = 11 \quad (\text{Not equal to 10})
\]
\[
9 + 9 = 18 \quad (\text{Not equal to 10})
\]
\[
1 + 6 = 7 \quad (\text{Not equal to 10})
\]
\[
2 + 4 = 6 \quad (\text{Not equal to 10})
\]
\[
5 + 9 = 14 \quad (\text{Not equal to 10})
\]
\[
2 + 6 = 8 \quad (\text{Not equal to 10})
\]

- None of the given facts equal 10. Again, this might be an error in the problem statement.

#### Fact 3: Sum = 1 + 7 = 8
- We need to find an addition fact that equals 8.
- From the given options:
\[
1 + 5 = 6 \quad (\text{Not equal to 8})
\]
\[
4 + 2 = 6 \quad (\text{Not equal to 8})
\]
\[
8 + 5 = 13 \quad (\text{Not equal to 8})
\]
\[
6 + 2 = 8 \quad (\text{Equal to 8})
\]
\[
7 + 4 = 11 \quad (\text{Not equal to 8})
\]
\[
9 + 9 = 18 \quad (\text{Not equal to 8})
\]
\[
1 + 6 = 7 \quad (\text{Not equal to 8})
\]
\[
2 + 4 = 6 \quad (\text{Not equal to 8})
\]
\[
5 + 9 = 14 \quad (\text{Not equal to 8})
\]
\[
2 + 6 = 8 \quad (\text{Equal to 8})
\]

- The addition facts that equal 8 are:
\[
6 + 2 = 8 \quad \text{and} \quad 2 + 6 = 8
\]

#### Fact 4: Sum = 30 + 6 = 36
- We need to find an addition fact that equals 36.
- From the given options:
\[
1 + 5 = 6 \quad (\text{Not equal to 36})
\]
\[
4 + 2 = 6 \quad (\text{Not equal to 36})
\]
\[
8 + 5 = 13 \quad (\text{Not equal to 36})
\]
\[
6 + 2 = 8 \quad (\text{Not equal to 36})
\]
\[
7 + 4 = 11 \quad (\text{Not equal to 36})
\]
\[
9 + 9 = 18 \quad (\text{Not equal to 36})
\]
\[
1 + 6 = 7 \quad (\text{Not equal to 36})
\]
\[
2 + 4 = 6 \quad (\text{Not equal to 36})
\]
\[
5 + 9 = 14 \quad (\text{Not equal to 36})
\]
\[
2 + 6 = 8 \quad (\text{Not equal to 36})
\]

- None of the given facts equal 36. This might be an error in the problem statement.

#### Fact 5: Sum = 8 + 2 = 10
- We need to find an addition fact that equals 10.
- From the given options:
\[
1 + 5 = 6 \quad (\text{Not equal to 10})
\]
\[
4 + 2 = 6 \quad (\text{Not equal to 10})
\]
\[
8 + 5 = 13 \quad (\text{Not equal to 10})
\]
\[
6 + 2 = 8 \quad (\text{Not equal to 10})
\]
\[
7 + 4 = 11 \quad (\text{Not equal to 10})
\]
\[
9 + 9 = 18 \quad (\text{Not equal to 10})
\]
\[
1 + 6 = 7 \quad (\text{Not equal to 10})
\]
\[
2 + 4 = 6 \quad (\text{Not equal to 10})
\]
\[
5 + 9 = 14 \quad (\text{Not equal to 10})
\]
\[
2 + 6 = 8 \quad (\text{Not equal to 10})
\]

- None of the given facts equal 10. This might be an error in the problem statement.

#### Fact 6: Sum = 9 + 5 = 14
- We need to find an addition fact that equals 14.
- From the given options:
\[
1 + 5 = 6 \quad (\text{Not equal to 14})
\]
\[
4 + 2 = 6 \quad (\text{Not equal to 14})
\]
\[
8 + 5 = 13 \quad (\text{Not equal to 14})
\]
\[
6 + 2 = 8 \quad (\text{Not equal to 14})
\]
\[
7 + 4 = 11 \quad (\text{Not equal to 14})
\]
\[
9 + 9 = 18 \quad (\text{Not equal to 14})
\]
\[
1 + 6 = 7 \quad (\text{Not equal to 14})
\]
\[
2 + 4 = 6 \quad (\text{Not equal to 14})
\]
\[
5 + 9 = 14 \quad (\text{Equal to 14})
\]
\[
2 + 6 = 8 \quad (\text{Not equal to 14})
\]

- The addition fact that equals 14 is:
\[
5 + 9 = 14
\]

---

Final Answer:

\[
\boxed{6, 7, 0, 6, 6, 0}
\]
For the addition facts:
- Sum = 8: \( 6 + 2 = 8 \) and \( 2 + 6 = 8 \)
- Sum = 14: \( 5 + 9 = 14 \)

If there are errors in the problem statement regarding the sums, please clarify. Otherwise, the solution is complete.