Addition: Combining two amounts to find the total
- Identify the amounts to add: $4.75 and $3.25
- Align decimal points and add
- Carry over if cents exceed 100
- Verify the answer
Solution: $4.75 + $3.25 = $8.00
$4.75
+ $3.25
75¢ + 25¢ = 100¢ = $1.00
$4 + $3 + $1 (carried over) = $8
$8 + $0.00 = $8.00
Verification: $8.00 - $3.25 = $4.75 ✓
Emma saved $8.00 in total
• Decimal Alignment: Align decimal points when adding
• Carrying: When cents exceed 100, carry over to dollars
• Verification: Check by subtracting one addend from the sum
Subtraction: Taking away one amount from another
Solution: $10.00 - $6.45 = $3.55
$10.00
- $6.45
$10.00 becomes $9.100¢ (since we need to borrow)
100¢ - 45¢ = 55¢
$9 - $6 = $3
Verification: $3.55 + $6.45 = $10.00 ✓
Marcus has $3.55 left
• Borrowing: When subtracting, borrow from the next place value
• Decimal Alignment: Align decimal points when subtracting
• Verification: Check by adding the difference to the subtrahend
Multiplication: Repeated addition of the same amount
Solution: $2.50 × 4 = $10.00
Sarah earns $2.50 each day
She works for 4 days
$2.50 × 4 = $10.00
$2.50 + $2.50 + $2.50 + $2.50 = $10.00 ✓
Verification: $10.00 ÷ 4 = $2.50 ✓
Sarah earns $10.00 in total
• Repeated Addition: Multiplication is adding the same number multiple times
• Decimal Multiplication: Count decimal places in the answer
• Verification: Check with division or repeated addition
Division: Splitting a total amount into equal parts
Solution: $8.00 ÷ 4 = $2.00 per friend
They found $8.00
There are 4 friends
$8.00 ÷ 4 = $2.00
$2.00 × 4 = $8.00 ✓
Verification: $2.00 × 4 = $8.00 ✓
Each friend gets $2.00
• Equal Sharing: Division splits a total into equal parts
• Decimal Division: Divide as if whole numbers, then place decimal
• Verification: Check with multiplication
Mixed Operations: Problems requiring multiple operations to solve
Solution: ($5.00 - $1.75 + $3.00) ÷ 2 = $3.13 each
$5.00 - $1.75 = $3.25
$3.25 + $3.00 = $6.25
$6.25 ÷ 2 = $3.125 ≈ $3.13
$3.13 × 2 = $6.26 (rounded from $6.25)
Verification: $3.13 × 2 = $6.26 ≈ $6.25 ✓
Tom and his sister each get $3.13
• Order of Operations: Perform operations from left to right
• Mixed Operations: Handle one operation at a time
• Rounding: Money typically rounded to nearest cent
Verification: Checking if your answer is correct using inverse operations
Inverse Operations: Operations that undo each other (addition/subtraction, multiplication/division)
Solution: The complete answer with step-by-step explanation
- Solve step-by-step: Show all work clearly
- State the answer: Present the final solution
- Verify solution: Check using inverse operation
- Confirm reasonableness: Ensure answer fits the problem context
• Addition: Sum - Addend = Other Addend
• Subtraction: Difference + Subtrahend = Minuend
• Multiplication: Product ÷ Factor = Other Factor
• Division: Quotient × Divisor = Dividend
Questions & Answers
Question: How do I know if my answer is correct when solving money word problems?
Answer: Use inverse operations to verify your answer:
- For addition: Subtract one addend from the sum to get the other addend
- For subtraction: Add the difference to the subtrahend to get the minuend
- For multiplication: Divide the product by one factor to get the other factor
- For division: Multiply the quotient by the divisor to get the dividend
Example: If $4.75 + $3.25 = $8.00, check: $8.00 - $3.25 = $4.75 ✓
Question: What should I do if my answer doesn't match the solution provided?
Answer: Follow these steps when your answer differs:
- Review the problem: Read it again to ensure you understood correctly
- Check your work: Go through each step carefully
- Identify the error: Look for calculation mistakes or wrong operation
- Try again: Solve the problem from scratch
- Verify: Use the inverse operation to check
Don't get discouraged - mistakes help you learn!
Question: How can I help students understand the importance of showing their work?
Answer: Explain the benefits of showing work:
- Tracking errors: Makes it easier to find mistakes
- Partial credit: Teachers can award points for correct steps
- Learning: Helps reinforce the problem-solving process
- Verification: Allows checking each step of the solution
Use the solutions as models for showing clear, organized work.
Solution: A complete answer with detailed steps and verification
Verification: Checking if your answer is correct using inverse operations
Inverse Operations: Operations that undo each other (addition/subtraction, multiplication/division)
Step-by-Step Solutions: Breaking problems into manageable parts with clear explanations
• Show Work: Always demonstrate your solution process clearly
• Verify Answers: Use inverse operations to check your work
• Include Units: Always include dollar signs and cents in your answer
• Check Reasonableness: Ensure your answer makes sense in the problem context
- Solve the problem: Work through each step carefully
- State the answer: Clearly identify the final solution
- Verify the solution: Use inverse operations to confirm
- Check reasonableness: Ensure the answer fits the problem context
• Always show your work step-by-step to track your thinking
• Use inverse operations to verify your answers
• Include units (dollars and cents) in your final answer
• Check that your answer makes sense in the context of the problem
• Practice regularly to build confidence with all operations