Solved Exercises on Simple Practice Troubleshooting in Grade 1

Master troubleshooting skills: identifying and fixing common mistakes in money problems through these 5 detailed exercises.

Troubleshooting Concepts & Strategies
🔍 FIND → FIX → VERIFY
Troubleshooting Process
Key Definitions:

Troubleshooting: Identifying, analyzing, and fixing problems in math solutions

Common Errors: Mistakes that frequently occur in money math problems

Verification: Checking if the answer is correct and reasonable

Systematic Approach: Following a structured method to solve problems

3-Step Troubleshooting Method:
  1. Find the Problem: Identify what went wrong
  2. Fix the Solution: Correct the mistake
  3. Verify the Answer: Check that it makes sense
Troubleshooting Workflow
1
FIND
2
FIX
3
VERIFY
Tip 1: Always check if your answer makes sense in the real world.
Tip 2: Count coins again if you think you made a mistake.
Tip 3: Use actual coins to verify your answer.
Tip 4: Look for common mistakes like adding instead of subtracting.
Solution: Exercises 1 to 3
1 Finding Counting Errors
Exercise 1
👧
Emma counted 2 quarters, 3 dimes, and 4 pennies. She said she had 85¢. Find and fix her mistake.
Problem Analysis:

Given: 2 quarters, 3 dimes, 4 pennies

Emma's Answer: 85¢

Task: Find and correct the error

Troubleshooting Steps:
  1. Find: Calculate the correct total
  2. Compare: See how Emma's answer differs
  3. Fix: Provide the correct answer
  4. Verify: Double-check the calculation
Step 1: Calculate correct value

2 quarters = 2 × 25¢ = 50¢

3 dimes = 3 × 10¢ = 30¢

4 pennies = 4 × 1¢ = 4¢

Correct total: 50¢ + 30¢ + 4¢ = 84¢

Step 2: Identify Emma's error

Emma said: 85¢

Correct: 84¢

Error: Emma counted 1¢ too much

Step 3: Fix the answer

Correct answer: 84¢

Step 4: Verify

50¢ + 30¢ + 4¢ = 84¢ ✓

Emma made an error. The correct amount is 84¢
Final answer:

Emma has 84¢, not 85¢. She counted 1¢ too much.

Applied rules:

• Multiplication: Number of coins × Value per coin

• Addition: Sum all coin values

• Verification: Double-check calculations

2 Finding Change Calculation Errors
Exercise 2
👦
Ben bought a toy for 45¢. He paid with 75¢ and got 20¢ back. Find and fix the error.
Problem Analysis:

Item Cost: 45¢

Payment: 75¢

Change Received: 20¢

Task: Verify if change is correct

Step 1: Calculate correct change

Payment - Cost = Change

75¢ - 45¢ = 30¢

Step 2: Identify Ben's error

Ben received: 20¢

Should have received: 30¢

Error: Ben got 10¢ less than he should have

Step 3: Fix the answer

Correct change: 30¢

Step 4: Verify

Cost + Change = Payment: 45¢ + 30¢ = 75¢ ✓

Ben should have received 30¢, not 20¢
Final answer:

Ben should have received 30¢ change, not 20¢. Someone made a calculation error.

Applied rules:

• Subtraction: Payment - Cost = Change

• Verification: Cost + Change = Payment

• Logic Check: Change should be less than payment

3 Finding Comparison Errors
Exercise 3
👧
Lucy has 60¢.
👦
Max has 45¢. A student said Max has more money. Find and fix the error.
Problem Analysis:

Lucy's Money: 60¢

Max's Money: 45¢

Incorrect Statement: Max has more money

Task: Correct the comparison

Step 1: Compare the amounts

Lucy: 60¢

Max: 45¢

60¢ > 45¢

Step 2: Identify the error

Incorrect: Max has more money

Correct: Lucy has more money

Step 3: Calculate the difference

60¢ - 45¢ = 15¢

Step 4: Fix the statement

Correct: Lucy has more money by 15¢

Lucy has more money by 15¢
Final answer:

Lucy has more money by 15¢. The student confused who had more.

Applied rules:

• Comparison: Compare values to determine greater amount

• Subtraction: Find difference between amounts

• Verification: Check that answer makes logical sense

Solution: Exercises 4 to 5
4 Finding Multi-Step Errors
Exercise 4
👧
Emma started with 50¢. She spent 20¢ on candy, then found 15¢ on the ground. A student said she ended with 45¢. Find and fix the error.
Problem Analysis:

Starting Amount: 50¢

Spent: 20¢

Found: 15¢

Student's Answer: 45¢

Task: Verify and correct the calculation

Step 1: Calculate correct final amount

Started with: 50¢

After spending: 50¢ - 20¢ = 30¢

After finding: 30¢ + 15¢ = 45¢

Step 2: Verify student's answer

Student said: 45¢

Actual calculation: 45¢

Actually, the student was correct!

Step 3: Verify the process

50¢ - 20¢ + 15¢ = 45¢ ✓

Step 4: Conclusion

No error found - student's answer is correct

Student's answer of 45¢ is correct
Final answer:

Emma ended with 45¢. The student's answer was correct. Sometimes there are no errors!

Applied rules:

• Sequential Operations: Follow events in chronological order

• Verification: Check that all steps are correct

• Conclusion: Sometimes there are no errors to fix

5 Finding Addition Errors
Exercise 5
👦
Tom bought a pencil for 25¢ and a notebook for 35¢. A student added and got 70¢ total. Find and fix any errors.
Problem Analysis:

Pencil Cost: 25¢

Notebook Cost: 35¢

Student's Total: 70¢

Task: Verify the addition

Step 1: Calculate correct total

25¢ + 35¢ = ?

20¢ + 30¢ = 50¢

5¢ + 5¢ = 10¢

Total: 50¢ + 10¢ = 60¢

Step 2: Identify the error

Student calculated: 70¢

Correct calculation: 60¢

Error: Student added incorrectly (possibly added 25 + 45 instead of 25 + 35)

Step 3: Fix the answer

Correct total: 60¢

Step 4: Verify

25¢ + 35¢ = 60¢ ✓

The correct total is 60¢, not 70¢
Final answer:

The correct total is 60¢, not 70¢. The student made an addition error.

Applied rules:

• Addition: Combine amounts carefully

• Verification: Double-check calculations

• Attention: Pay careful attention to numbers

Questions & Answers

Question: I often make mistakes when counting money. How can I check if I counted correctly?

Answer: Here are effective ways to check your counting:

  • Count Again: Count the same coins a second time to verify
  • Group by Type: Put same coins together and count each group separately
  • Use Skip Counting: Count dimes by 10s, nickels by 5s, quarters by 25s
  • Check Your Work: Add up the groups to make sure they match your total
  • Use Real Coins: If possible, use actual coins to verify your answer

Example: For 2 quarters, 3 dimes: 25, 50 (quarters) + 60, 70, 80 (dimes) = 80¢

Question: My child often gets confused when making change. How can I help them troubleshoot these problems?

Answer: Here are troubleshooting strategies for change problems:

  1. Identify the Formula: Change = Payment - Cost
  2. Check Units: Make sure both amounts are in same units (cents or dollars)
  3. Verify Logic: Change should always be less than the payment
  4. Test Your Answer: Cost + Change should equal Payment
  5. Use Real Money: Practice with actual coins to build understanding

For example: If item costs 30¢ and you pay 50¢, change should be 20¢. Check: 30¢ + 20¢ = 50¢ ✓

Question: What are the most common errors students make in money troubleshooting problems?

Answer: Common troubleshooting errors include:

  • Counting Errors: Miscounting coins or mixing up coin values
  • Operation Confusion: Adding when they should subtract (or vice versa)
  • Unit Confusion: Mixing cents and dollars incorrectly
  • Place Value Errors: Misplacing decimal points in dollar amounts
  • Comparison Mistakes: Confusing which amount is greater/less
  • Verification Issues: Not checking if answers make sense

The key is teaching students to slow down, verify their work, and use multiple strategies to confirm their answers.