Multi-Digit Operations: Mathematical operations (addition, subtraction, multiplication, division) performed with numbers that have more than one digit.
Place Value: The value of a digit based on its position in the number (ones, tens, hundreds, thousands, etc.).
Regrouping: Carrying over or borrowing from higher place values during operations.
Partial Products: Breaking down multiplication into smaller parts based on place value.
Line up numbers by place value
Add digits column by column
Carry over when sum ≥ 10
Line up numbers by place value
Subtract digits column by column
Borrow when needed
Multiply each digit of the bottom number
Shift partial products
Add all partial products
- Align numbers: Line up numbers by place value (rightmost digits aligned)
- Start from right: Begin calculations in the ones place
- Move left: Work through each place value column
- Regroup when needed: Carry over for addition, borrow for subtraction
- Check your work: Verify using inverse operations or estimation
Ones (1)
Tens (10)
Hundreds (100)
Thousands (1,000)
Ten Thousands (10,000)
Addition: Subtract one addend from sum
Subtraction: Add subtrahend to difference
Multiplication: Divide product by one factor
Division: Multiply quotient by divisor
- Always align numbers properly by place value
- Work slowly and carefully to avoid mistakes
- Check your work by using inverse operations
- Estimate first to see if your answer makes sense
- Practice regrouping/borrowing regularly
- Use scratch paper to organize your work
- Pay attention to place value when multiplying
Multi-digit addition: Adding numbers with multiple digits, working from right to left and carrying over when necessary
- Align numbers by place value
- Add digits in each column from right to left
- Carry over when sum is 10 or greater
- Continue until all columns are added
4,287
+ 3,569
------
7 + 9 = 16 → Write 6, carry 1
8 + 6 + 1 = 15 → Write 5, carry 1
2 + 5 + 1 = 8
4 + 3 = 7
4,287 + 3,569 = 7,856
• Place value alignment: Numbers lined up by place value
• Carrying: When sum ≥ 10, carry the tens digit to next column
• Verification: 7,856 - 3,569 = 4,287 ✓
Multi-digit subtraction: Subtracting numbers with multiple digits, working from right to left and borrowing when necessary
8,432
- 5,768
------
Need to borrow: 12 - 8 = 4
After borrowing: 12 - 6 = 6
After borrowing: 13 - 7 = 6
7 - 5 = 2
8,432 - 5,768 = 2,664
• Place value alignment: Numbers lined up by place value
• Borrowing: When top digit is smaller, borrow from next column
• Verification: 2,664 + 5,768 = 8,432 ✓
Multi-digit multiplication: Multiplying numbers with multiple digits using partial products and place value
347 × 6 = 2,082
347 × 20 = 6,940
2,082 + 6,940 = 9,022
347 × 26 = 9,022
• Partial products: Multiply each digit separately
• Place value: Shift second row one place to the left
• Verification: 9,022 ÷ 26 = 347 ✓
Addition: Combining two or more numbers to find their total
Subtraction: Finding the difference between two numbers
Multiplication: Repeated addition of the same number
Division: Splitting a number into equal groups
- Identify operation: Determine which operation to perform
- Align numbers: Line up by place value
- Follow algorithm: Use the appropriate method for the operation
- Check work: Verify using inverse operation
• Alignment: Always line up numbers by place value
• Carrying: In addition, carry when sum ≥ 10
• Borrowing: In subtraction, borrow when top digit is smaller
• Partial products: In multiplication, multiply each digit separately
Multi-digit division: Dividing larger numbers using the standard algorithm, finding how many times the divisor fits into the dividend
Divide 8,924 by 12
12 goes into 89 seven times (7 × 12 = 84)
89 - 84 = 5, bring down 2 → 52
12 goes into 52 four times (4 × 12 = 48)
52 - 48 = 4, bring down 4 → 44
12 goes into 44 three times (3 × 12 = 36), remainder 8
8,924 ÷ 12 = 743 R 8
• Division algorithm: Divide, multiply, subtract, bring down
• Remainder: What's left after last subtraction
• Verification: 743 × 12 + 8 = 8,916 + 8 = 8,924 ✓
Mixed operations: Problems that combine different mathematical operations, following order of operations
2,437 + 1,896 = 4,333
4,333 - 1,542 = 2,791
2,437 + 1,896: 7 + 6 = 13 → carry 1, continue...
4,333 - 1,542: Need to borrow in tens place...
(2,437 + 1,896) - 1,542 = 2,791
• Order of operations: Parentheses first
• Addition algorithm: Add from right to left with carrying
• Subtraction algorithm: Subtract from right to left with borrowing