Mixed Addition and Subtraction math worksheet with a playful bird illustration.

The image you uploaded appears to be a worksheet titled "Mixed Addition and Subtraction." It contains a series of numerical problems involving addition and subtraction. Below, I will explain how to solve these types of problems step by step.

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General Approach to Solving Mixed Addition and Subtraction Problems

1. Identify the Operation: Determine whether the problem involves addition (+) or subtraction (−).
2. Align the Numbers: If the numbers are multi-digit, align them vertically so that the digits in the same place value are in the same column.
3. Perform the Calculation:
- For addition, add the digits in each column from right to left, carrying over any excess to the next column if necessary.
- For subtraction, subtract the digits in each column from right to left, borrowing from the next column if necessary.
4. Check Your Work: Verify your calculations to ensure accuracy.

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Example Problems and Solutions

#### Problem 1: 157 + 645 + 365
- Align the numbers:
```
157
+645
+365
------
```
- Add column by column:
- Units: \( 7 + 5 + 5 = 17 \) → Write 7, carry 1.
- Tens: \( 5 + 4 + 6 + 1 (\text{carry}) = 16 \) → Write 6, carry 1.
- Hundreds: \( 1 + 6 + 3 + 1 (\text{carry}) = 11 \) → Write 11.
- Result: \( 157 + 645 + 365 = 1167 \).

#### Problem 2: 235 − 129
- Align the numbers:
```
235
-129
------
```
- Subtract column by column:
- Units: \( 5 - 9 \). Since 5 is less than 9, borrow 1 from the tens place (3 becomes 2, and 5 becomes 15). \( 15 - 9 = 6 \).
- Tens: \( 2 - 2 = 0 \).
- Hundreds: \( 2 - 1 = 1 \).
- Result: \( 235 - 129 = 106 \).

#### Problem 3: 456 + 728 − 193
- Perform addition first:
- \( 456 + 728 = 1184 \).
- Then subtract:
- \( 1184 - 193 = 991 \).
- Result: \( 456 + 728 - 193 = 991 \).

#### Problem 4: 987 − 345 + 231
- Perform subtraction first:
- \( 987 - 345 = 642 \).
- Then add:
- \( 642 + 231 = 873 \).
- Result: \( 987 - 345 + 231 = 873 \).

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Key Takeaways

- Always follow the order of operations if there are multiple steps.
- Be careful with borrowing and carrying when dealing with multi-digit numbers.
- Double-check your work to avoid simple mistakes.

If you need solutions for specific problems from the worksheet, please let me know, and I can provide detailed steps for those as well!

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Final Answer:
\[
\boxed{\text{Solutions depend on the specific problems; follow the steps above to solve them.}}
\]