Problem Context:
This is a subtraction problem because we need to find how many books REMAIN after some were borrowed.
Key Information:
- Starting number of books: 847
- Books borrowed: 235
- Question: How many books are LEFT?
Operation:
We need to SUBTRACT the borrowed books from the total books: 847 - 235
-235
Tens: 4 - 3 = 1
Hundreds: 8 - 2 = 6
The library started with 847 books and 235 were borrowed.
We need to find how many books are LEFT in the library.
Since books were taken away, we use subtraction: 847 - 235
847 - 235 = 612
There are 612 books left in the library.
There are 612 books left in the library.
• Keywords: "left", "remain", "how many are left" indicate subtraction
• Context Clue: Something being taken away suggests subtraction
• Place Value: Align numbers correctly when solving
Problem Context:
This is a subtraction problem because fish were given away, so we need to find how many are left.
Key Information:
- Initial number of fish: 520
- Fish given away: 186
- Question: How many fish are REMAINING?
Operation:
We need to SUBTRACT the given fish from the total fish: 520 - 186
-186
Tens: 11 - 8 = 3
Hundreds: 4 - 1 = 3
The fish tank started with 520 fish and 186 were given away.
We need to find how many fish are REMAINING in the tank.
Since fish were given away, we use subtraction: 520 - 186
520 - 186 = 334
There are 334 fish remaining in the tank.
There are 334 fish remaining in the tank.
• Keywords: "remaining", "given away", "how many are left" indicate subtraction
• Regrouping: When top number < bottom number, borrow from higher place value
• Zero Handling: When borrowing from zero, go to next non-zero place value
Problem Context:
This is a subtraction problem because apples were sold, so we need to find how many are left to sell.
Key Information:
- Total apples grown: 7,425
- Apples sold: 2,198
- Question: How many apples are LEFT to sell?
Operation:
We need to SUBTRACT the sold apples from the total apples: 7,425 - 2,198
-2,198
Tens: 11 - 9 = 2
Hundreds: 3 - 1 = 2
Thousands: 6 - 2 = 4
The orchard grew 7,425 apples and sold 2,198 apples.
We need to find how many apples are LEFT to sell.
Since apples were sold, we use subtraction: 7,425 - 2,198
7,425 - 2,198 = 5,227
The farmers have 5,227 apples left to sell.
The farmers have 5,227 apples left to sell.
• Keywords: "left to sell", "how many remain", "sold" indicate subtraction
• Four-Digit Subtraction: Same principles apply to larger numbers
• Regrouping Chain: May need to regroup across multiple place values
Word Problem: A math problem presented in the form of a story or real-world situation
Key Information: The important numbers and facts needed to solve the problem
Keywords: Words that suggest which operation to use (subtract, add, multiply, divide)
Context: The real-world situation described in the problem
Subtraction Keywords: Words like "left," "remaining," "how many are left," "less than," "gave away," "sold," "borrowed," "used," etc.
- Read the problem carefully: Understand what is happening in the story
- Identify key information: Find the numbers and important facts
- Look for keywords: Find words that suggest subtraction
- Determine what to find: What is the question asking?
- Set up the equation: Write the subtraction problem
- Solve the subtraction: Use proper subtraction methods
- Answer the question: Write a complete sentence with the answer
• Read Thoroughly: Understand the context before solving
• Keyword Recognition: Identify words that suggest subtraction
• Information Extraction: Pull out relevant numbers and facts
• Equation Setup: Write the correct subtraction problem
• Proper Execution: Use correct subtraction methods including regrouping
• Complete Answer: Answer the specific question in context
Problem Context:
This is an addition problem because miles are being ADDED to the car's total mileage.
Key Information:
- Starting mileage: 24,560 miles
- Miles driven: 12,847 miles
- Question: What is the NEW mileage?
Operation:
We need to ADD the driven miles to the starting mileage: 24,560 + 12,847
+12,847
The car had 24,560 miles and Mr. Johnson drove 12,847 more miles.
We need to find the NEW total mileage on the car.
Since miles are being ADDED to the total, we use addition: 24,560 + 12,847
24,560 + 12,847 = 37,407
The new mileage on his car is 37,407 miles.
The new mileage on his car is 37,407 miles.
• Context Matters: "Drove" means adding miles, not subtracting
• Keyword Analysis: "What is the new..." often indicates addition
• Problem Understanding: Always consider the real-world context
Problem Context:
This is a subtraction problem because money was withdrawn, so we need to find how much remains.
Key Information:
- Starting amount: $3,250
- Amount withdrawn: $876
- Question: How much money is LEFT in the account?
Operation:
We need to SUBTRACT the withdrawn amount from the starting amount: $3,250 - $876
-$876
Tens: 14 - 7 = 7
Hundreds: 11 - 8 = 3
Thousands: 2 - 0 = 2
Sarah had $3,250 in her account and withdrew $876.
We need to find how much money is LEFT in her account.
Since money was withdrawn, we use subtraction: $3,250 - $876
$3,250 - $876 = $2,374
Sarah has $2,374 left in her account.
Sarah has $2,374 left in her account.
• Keywords: "withdrawn", "left", "remaining" indicate subtraction
• Money Problems: Same subtraction principles apply
• Regrouping Chain: May need to regroup across multiple place values
Word Problem: A mathematical problem presented in a narrative format describing a real-world situation.
Context: The real-world scenario that gives meaning to the numbers and operations in the problem.
Keywords: Words that indicate which mathematical operation to perform (addition, subtraction, multiplication, division).
Subtraction Keywords: Words like "left," "remaining," "how many are left," "less than," "gave away," "sold," "borrowed," "used," "withdrawn," "taken away," etc.
Key Information: The important numbers and facts needed to solve the problem.
- Read carefully: Understand the story and what is happening
- Identify key information: Circle or note important numbers and facts
- Look for keywords: Find words that suggest the operation needed
- Determine the question: Understand what the problem is asking for
- Set up the equation: Write the mathematical expression
- Solve the math: Perform the calculation correctly
- Check context: Make sure the answer makes sense in the story
- Answer completely: Provide the answer in a complete sentence
• Context Understanding: Always consider the real-world situation described
• Keyword Recognition: Learn to identify words that suggest subtraction
• Information Organization: Separate known facts from the unknown
• Operation Selection: Choose the correct mathematical operation
• Calculation Accuracy: Perform math operations correctly including regrouping
• Answer Verification: Check that the answer makes sense in context
• Complete Response: Answer the question fully and in context