Math worksheet for decomposing numbers using number bonds, with questions and multiple-choice options.

Problem Analysis and Solution

The task involves decomposing numbers using number bonds. Number bonds are a visual representation of how numbers can be split into parts. The goal is to find the missing part in each number bond.

#### Question 1: What is the sum of 10 and 20?
- This is a straightforward addition problem.
- \( 10 + 20 = 30 \).

Correct Answer: D (30)

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#### Question 2: What is the missing number?
- The number bond shows:
- Total: 157
- One part: 7
- Missing part: ?

To find the missing part, subtract the known part from the total:
\[ 157 - 7 = 150 \]

Correct Answer: C (150)

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#### Question 3: What is the missing number?
- The number bond shows:
- Total: 392
- One part: 2
- Missing part: ?

To find the missing part, subtract the known part from the total:
\[ 392 - 2 = 390 \]

Correct Answer: D (390)

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#### Question 4: What is the missing number?
- The number bond shows:
- Total: 418
- One part: 10
- Missing part: ?

To find the missing part, subtract the known part from the total:
\[ 418 - 10 = 408 \]

Correct Answer: D (408)

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Final Answers:

1. D (30)
2. C (150)
3. D (390)
4. D (408)

Boxed Final Answers:
\[
\boxed{D, C, D, D}
\]