Long Division: Divide-Multiply-Subtract-Bring Down
Long division breaks division into repeated steps: divide the working number by the divisor, multiply, subtract, bring down. The quotient is built digit by digit. Remainder is always less than the divisor. Verification: QรD+R=Dividend.
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Verification: Quotient ร Divisor + Remainder = Dividend. The obelus รท was introduced by Johann Rahn in 1659. Decimal places extend the quotient for fractional results.
Ready to run the numbers?
Why: Long division handles large numbers that mental math cannot. Used in finance, measurement, sharing, and scaling. The algorithm is foundational for polynomial division.
How: Repeat: divide working number by divisor to get quotient digit; multiply that digit by divisor; subtract from working number; bring down next digit. Remainder is always less than divisor.
Run the calculator when you are ready.
Enter Numbers
Quotient vs Remainder
Quotient & Remainder Proportions
๐ Traditional Long Division Format
๐ Step-by-Step (Divide-Multiply-Subtract-Bring Down)
๐ Step-by-Step Breakdown
For educational and informational purposes only. Verify with a qualified professional.
๐งฎ Fascinating Math Facts
Dividend รท Divisor = Quotient R Remainder
โ Basic division
Always verify: QรD+R=Dividend
โ Check your work
๐ Key Takeaways
- โข Long division breaks division into repeated divide, multiply, subtract, bring down steps
- โข The remainder is what's left when the divisor no longer fits โ always less than the divisor
- โข Verification: Quotient ร Divisor + Remainder = Dividend
- โข Decimal places extend the quotient for fractional results (e.g., 100 รท 7 = 14.2857โฆ)
- โข When the divisor doesn't fit, write 0 in the quotient and bring down the next digit
๐ก Did You Know?
๐ How Long Division Works
Long division is an algorithm that divides large numbers by repeatedly: (1) Divide the current working number by the divisor to get a quotient digit, (2) Multiply that digit by the divisor, (3) Subtract from the working number, (4) Bring down the next digit. Repeat until all digits are processed.
Verification
Quotient ร Divisor + Remainder = Dividend. This confirms your answer is correct.
๐ Worked Example: 100 รท 7
Setup: Divide 100 by 7. Write 7 on the left, 100 under the bracket.
Step 1: 7 into 1? Zero. Bring down 0. Working: 10.
Step 2: 7 into 10? Once. Multiply: 7ร1=7. Subtract: 10โ7=3.
Step 3: Bring down 0. Working: 30.
Step 4: 7 into 30? Four times. Multiply: 7ร4=28. Subtract: 30โ28=2.
Result: Quotient = 14, Remainder = 2. So 100 รท 7 = 14 R 2, or 14.2857โฆ as decimal.
Verification: 14 ร 7 + 2 = 98 + 2 = 100 โ
๐ Real-World Applications
๐ฐ Finance & Splitting
Dividing bills, per-unit cost, profit per share, loan payments.
๐ Data & Rates
Averages, rates per unit, percentages, scaling down.
๐๏ธ Construction
Tiles per row, materials per section, spacing calculations.
๐ Retail
Price per unit, bulk discounts, inventory allocation.
๐ฌ Science
Concentrations, rates, unit conversions, ratios.
โฑ๏ธ Time & Speed
Distance รท time = speed, work รท rate = time.
โ ๏ธ Common Mistakes to Avoid
- Forgetting the remainder: Always check if there is a remainder. 100 รท 7 = 14 R 2, not just 14.
- Wrong quotient digit: Use the largest multiple of the divisor that fits. For 30 รท 7, use 4 (7ร4=28), not 3 or 5.
- Not verifying: Always verify: Quotient ร Divisor + Remainder = Dividend.
- Division by zero: Never divide by 0. It is undefined.
- Misaligning digits: Keep the quotient digits aligned above the correct dividend digits.
๐ฏ Expert Tips
๐ก Estimate First
Before dividing, estimate. For 100 รท 7, 7ร14=98, so quotient โ 14. Helps catch errors.
๐ก Remainder as Fraction
Enable "Show remainder as fraction" to see remainder in lowest terms. E.g., 2/7 for 100รท7.
๐ก Decimal Places
For repeating decimals, increase decimal places to see the pattern. 1รท3 = 0.333โฆ
๐ก Zero in Quotient
When the divisor doesn't fit, write 0 and bring down the next digit. E.g., 56 doesn't fit into 12.
๐ Reference Table
| Example | Quotient | Remainder |
|---|---|---|
| 100 รท 7 | 14 | 2 |
| 1234 รท 56 | 22 | 2 |
| 999 รท 3 | 333 | 0 |
| 50000 รท 123 | 406 | 62 |
| 7 รท 3 | 2 | 1 |
| 144 รท 12 | 12 | 0 |
๐ Quick Reference
๐ Practice Problems
โ FAQ
What is the remainder in long division?
The remainder is the amount left over after the divisor has been subtracted as many times as possible from the dividend. It is always less than the divisor.
How do I get a decimal result?
Use Advanced mode and increase "Decimal places". The calculator continues division by appending zeros to the remainder and computing more digits.
Why does verification matter?
Verification (Quotient ร Divisor + Remainder = Dividend) proves your division was performed correctly. If it doesn't check out, there was an error.
What is the difference between quotient and remainder?
The quotient is how many times the divisor fits. The remainder is what is left. For 100รท7, quotient=14, remainder=2 โ 7 fits 14 times with 2 left.
When should I use remainder as fraction?
Enable "Show remainder as fraction" in Advanced mode for fractional form. E.g., 100รท7 gives 2/7, so exact result is 14 2/7.
Can I divide by decimals?
This calculator uses integers only. For decimal division, multiply both by a power of 10 to make them integers, then divide and adjust.
What is the divide-multiply-subtract-bring down cycle?
The core long division loop: (1) Divide working number by divisor, (2) Multiply quotient digit by divisor, (3) Subtract from working number, (4) Bring down next digit. Repeat.
๐ Summary
Long division divides large numbers using the repeated cycle: divide, multiply, subtract, bring down. The quotient is built digit by digit. The remainder is always less than the divisor. Verification (QรD+R=Dividend) confirms correctness. Decimal places extend the result for fractional answers. Master this algorithm for arithmetic fluency and as a foundation for polynomial division.
โ Verification Tip
Always verify: Quotient ร Divisor + Remainder = Dividend. Estimate first โ e.g., 100รท7 โ 14 โ to catch major errors. For exact division (remainder 0), multiply quotient by divisor to confirm.
๐ Next Steps
After mastering long division, try the Long Multiplication Calculator for the inverse operation, or the Remainder Calculator for modulo. The Long Addition Calculator helps with the subtraction step.
โ ๏ธ Disclaimer: This calculator performs integer division. For very large numbers, JavaScript number precision limits may apply. Results are for educational purposes. Always verify critical calculations.
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