One-step problem: A problem that requires only one mathematical operation to solve
- Identify the amounts to be added
- Align decimal points
- Add the amounts column by column
- Include the dollar sign in the answer
Sarah starts with $3.50 and gets $2.25 more
$3.50 + $2.25
$3.50 + $2.25 = $5.75
Sarah has $5.75
Sarah has $5.75
• One operation: Only addition is needed
• Decimal alignment: Align decimal points when adding money
• Context: Getting more money means addition
Subtraction: Taking away or finding the difference between amounts
Tom starts with $10.00
He spends $4.75
$10.00 - $4.75
$10.00 - $4.75 = $5.25
Tom has $5.25 left
Tom has $5.25 left
• One operation: Only subtraction is needed
• Decimal alignment: Align decimal points when subtracting
• Context: Spending money means subtraction
Multiplication: Repeated addition; finding total when you have equal groups
Emma bought 3 notebooks
Each notebook costs $1.50
3 × $1.50
3 × $1.50 = $4.50
Emma spent $4.50 in total
Emma spent $4.50 in total
• One operation: Only multiplication is needed
• Unit pricing: Multiply quantity by unit price
• Context: Equal groups mean multiplication
One-step problem: Requires only one mathematical operation to solve
Unit price: Cost of one item (e.g., $2.50 per apple)
Total cost: Sum of all expenses
- Read the problem: Understand what is being asked
- Identify key information: Note all numbers and operations needed
- Choose the operation: Decide whether to add, subtract, multiply, or divide
- Solve the problem: Perform the single operation
- State the answer: Include the correct units and dollar sign
• Addition: total, altogether, in all, combined, more, earned, received
• Subtraction: left, remaining, spent, cost, difference, less
• Multiplication: each, per, groups of, times, total cost
• Division: shared equally, divided, per person, split
Division: Splitting a total amount into equal parts
Jake has $12.00
He wants to share among 4 weeks
$12.00 ÷ 4
$12.00 ÷ 4 = $3.00
Jake can spend $3.00 each week
Jake can spend $3.00 each week
• One operation: Only division is needed
• Equal sharing: Division splits into equal parts
• Context: "Shared equally" indicates division
Comparison: Finding the difference between two amounts
Lisa has $8.50 (the larger amount)
Mark has $5.25 (the smaller amount)
$8.50 - $5.25
$8.50 - $5.25 = $3.25
Lisa has $3.25 more than Mark
Lisa has $3.25 more than Mark
• One operation: Only subtraction is needed
• Comparison: Subtract smaller from larger
• Context: "How much more" indicates subtraction
One-step problem: A mathematical problem that can be solved using only one operation (addition, subtraction, multiplication, or division).
Clue words: Words in the problem that indicate which operation to use.
Unit price: The cost of one item. Example: $2.50 per apple.
Total cost: The sum of all individual costs. Example: 3 apples at $2.50 each = $7.50 total.
• Single operation: One-step problems require only one mathematical operation.
• Decimal alignment: Always align decimal points when adding or subtracting money.
• Operation identification: Look for clue words to determine the correct operation.
• Context matters: Real-world situations guide the choice of operation.
1. Read the problem: Understand what is being asked.
2. Identify numbers: Find all the monetary amounts in the problem.
3. Find clue words: Look for words that suggest the operation to use.
4. Choose operation: Select the correct mathematical operation.
5. Calculate: Perform the single operation accurately.
6. State answer: Include the dollar sign and proper units.
Simple Addition: $2.00 + $3.00 = $5.00
Simple Subtraction: $10.00 - $4.50 = $5.50
Simple Multiplication: 4 items × $1.25 each = $5.00
Simple Division: $8.00 ÷ 4 people = $2.00 per person
• Clue word patterns: "Total" and "altogether" usually mean addition; "left" and "remaining" usually mean subtraction.
• Estimate first: Round numbers to estimate your answer before calculating precisely.
• Draw pictures: Visual representations can clarify the problem.
• Check reasonableness: Ask if your answer makes sense in the real world.
• Misaligning decimal points during addition/subtraction
• Choosing the wrong operation due to misinterpreting clue words
• Forgetting to include the dollar sign in the answer
• Not reading the question completely to understand what is being asked
• One-step problems require only one operation to solve
• "Each" and "per" often indicate multiplication or division
• "How many more" and "difference" indicate subtraction
• Always align decimal points when working with money
Questions & Answers
Question: How do I know which operation to use in a one-step money problem?
Answer: Look for clue words in the problem:
- Addition: "total," "altogether," "in all," "more," "earned," "received"
- Subtraction: "left," "remaining," "spent," "cost," "difference," "less"
- Multiplication: "each," "per," "groups of," "times," "total cost"
- Division: "shared equally," "divided," "per person," "split," "each"
Also consider the real-world situation: getting money = addition, spending money = subtraction.
Question: What if I see the word "each" in a problem? Does that always mean multiplication?
Answer: Usually "each" means multiplication, but context matters:
- "3 items at $2.00 each" → 3 × $2.00 = $6.00 (multiplication)
- "$12.00 shared equally among 4 people" → $12.00 ÷ 4 = $3.00 each (division)
- "How much does each person get?" → This follows a division problem
Always read the full problem to understand the situation!
Question: Why is it important to align decimal points when adding or subtracting money?
Answer: Aligning decimal points ensures accuracy:
- Keeps dollars with dollars and cents with cents
- Prevents place value errors
- Makes carrying and borrowing easier
- Matches standard mathematical procedure
Example: $3.50 + $2.25 should be written vertically with decimal points aligned to get $5.75, not $57.50!