Long Division Calculator

Perform long division with step-by-step explanations

Long Division Calculator

Enter a dividend and divisor to see the quotient, remainder, and step-by-step solution.

What Is Long Division?

Long division is a standard method for dividing large numbers that breaks the problem into a series of easier steps. Unlike simple division that you can do in your head, long division writes out each step explicitly, making it possible to divide any two whole numbers—regardless of size.

The result of long division has two parts:

  • Quotient: The whole number result (how many times the divisor fits into the dividend)
  • Remainder: What's left over after division (the part that can't be evenly divided)
Dividend ÷ Divisor = Quotient remainder Remainder

How to Do Long Division: The Four Steps

Long division follows a repeating cycle of four steps. The mnemonic "Divide, Multiply, Subtract, Bring down" (sometimes remembered as "Does McDonald's Sell Burgers?") helps you remember the sequence.

  1. Divide: Determine how many times the divisor fits into the current working number (starting with the leftmost digits of the dividend).
  2. Multiply: Multiply the divisor by the number from step 1. Write this product below your working number.
  3. Subtract: Subtract the product from your working number.
  4. Bring down: Bring down the next digit from the dividend. This creates your new working number. Repeat from step 1.

Continue until there are no more digits to bring down. The final subtraction result is your remainder.

Worked Examples

Example 1: 125 ÷ 8
Setup: 125 ÷ 8
15 R 5 ┌──────── 8 │ 125 │ 8 (8 × 1 = 8) │ ─── │ 45 (12 - 8 = 4, bring down 5) │ 40 (8 × 5 = 40) │ ─── │ 5 ← Remainder

Step-by-step:

  1. 8 doesn't fit into 1, so look at 12. 8 fits into 12 once (8 × 1 = 8). Write 1 above the 2.
  2. Subtract: 12 - 8 = 4.
  3. Bring down the 5 to make 45.
  4. 8 fits into 45 five times (8 × 5 = 40). Write 5 above the 5.
  5. Subtract: 45 - 40 = 5. No more digits to bring down.

Answer: 125 ÷ 8 = 15 remainder 5 (or 15.625 as a decimal)

Check: (15 × 8) + 5 = 120 + 5 = 125 ✓

Example 2: 2847 ÷ 23
Setup: 2847 ÷ 23
123 R 18 ┌────────── 23 │ 2847 │ 23 (23 × 1 = 23) │ ─── │ 54 (28 - 23 = 5, bring down 4) │ 46 (23 × 2 = 46) │ ─── │ 87 (54 - 46 = 8, bring down 7) │ 69 (23 × 3 = 69) │ ─── │ 18 ← Remainder

Answer: 2847 ÷ 23 = 123 remainder 18

Check: (123 × 23) + 18 = 2829 + 18 = 2847 ✓

Example 3: 504 ÷ 7 (No remainder)
Setup: 504 ÷ 7
72 ┌─────── 7 │ 504 │ 49 (7 × 7 = 49) │ ─── │ 14 (50 - 49 = 1, bring down 4) │ 14 (7 × 2 = 14) │ ─── │ 0 ← No remainder

Answer: 504 ÷ 7 = 72 (exactly, no remainder)

When a number divides evenly, we say it's a factor. 7 is a factor of 504.

Example 4: 53 ÷ 100 (Dividend smaller than divisor)

When the dividend is smaller than the divisor, the quotient is 0 and the entire dividend becomes the remainder.

Answer: 53 ÷ 100 = 0 remainder 53

As a decimal: 0.53. As a fraction: 53/100.

Common Mistakes to Avoid

Mistake 1: Forgetting to write 0 in the quotient

When the divisor doesn't fit into the current working number, you must write 0 in the quotient and bring down the next digit. For example, in 1008 ÷ 4, the middle zeros matter: the answer is 252, not 252 without proper placement.

Mistake 2: Subtracting incorrectly

Always double-check subtraction, especially when borrowing is needed. A subtraction error early on will make every subsequent step wrong.

Mistake 3: Estimating the wrong quotient digit

If your multiplication produces a number larger than your working number, your estimate is too high. If subtracting leaves a remainder larger than the divisor, your estimate is too low. Adjust and recalculate.

Mistake 4: Forgetting to bring down all digits

Always bring down exactly one digit at a time. Skipping digits or bringing down multiple at once will give incorrect results.

How to Verify Your Answer

Always check long division by reversing the process:

(Quotient × Divisor) + Remainder = Dividend

If this equation holds true, your division is correct. If not, go back and check each step for errors.

Example verification: For 125 ÷ 8 = 15 R 5
Check: (15 × 8) + 5 = 120 + 5 = 125 ✓

Converting Remainders to Decimals

To express a division result as a decimal instead of using a remainder:

  1. After reaching the remainder, add a decimal point to the quotient
  2. Add a zero after the remainder (or after the decimal in the dividend)
  3. Continue dividing as normal
  4. Repeat until the remainder is 0, or until you have enough decimal places
Example: 125 ÷ 8 as a decimal

125 ÷ 8 = 15 R 5

Continue: 50 ÷ 8 = 6 R 2 → 15.6

Continue: 20 ÷ 8 = 2 R 4 → 15.62

Continue: 40 ÷ 8 = 5 R 0 → 15.625 ✓

Note: Some divisions produce repeating decimals (like 1 ÷ 3 = 0.333...). In these cases, you can round to a practical number of decimal places or express the result as a fraction.

Frequently Asked Questions

What is long division?

Long division is a method for dividing large numbers by breaking the problem into a series of smaller, easier steps. It involves repeatedly dividing, multiplying, and subtracting until no digits remain, producing a quotient and possibly a remainder.

How do you do long division step by step?

Long division follows four repeating steps: (1) Divide—determine how many times the divisor fits into the current portion of the dividend; (2) Multiply—multiply the divisor by that number; (3) Subtract—subtract the product from the current portion; (4) Bring down—bring down the next digit and repeat until no digits remain.

What is the difference between quotient and remainder?

The quotient is the main answer to a division problem—how many whole times the divisor fits into the dividend. The remainder is what's left over after the division is complete, representing the portion of the dividend that cannot be evenly divided.

How do you check if a long division answer is correct?

Multiply the quotient by the divisor, then add the remainder. The result should equal the original dividend. Formula: (Quotient × Divisor) + Remainder = Dividend. For example, 125 ÷ 8 = 15 R 5 can be verified: (15 × 8) + 5 = 120 + 5 = 125.

What happens when the dividend is smaller than the divisor?

When the dividend is smaller than the divisor, the quotient is 0 and the remainder equals the dividend. For example, 5 ÷ 8 = 0 remainder 5, because 8 does not fit into 5 at all.

Can you do long division with decimals?

Yes. To continue dividing past the remainder, add a decimal point to the quotient and zeros to the remainder, then continue the division process. For example, 125 ÷ 8 = 15.625 when carried out to three decimal places.

Why is long division important to learn?

Long division builds foundational understanding of how division works and develops number sense. It's essential for polynomial division in algebra, understanding ratios and proportions, and working with fractions. The systematic approach also strengthens problem-solving skills.

What is the difference between long division and short division?

Short division is a condensed form where intermediate calculations are done mentally and only the quotient is written. Long division writes out every step explicitly, making it easier to follow and learn from, especially with larger numbers.

What does "R" mean in division?

"R" stands for "remainder." When you see 15 R 5, it means the quotient is 15 and the remainder is 5. The remainder is what's left over when the dividend cannot be evenly divided by the divisor.

How do I handle zeros in long division?

When the divisor doesn't fit into your current working number, write 0 in the quotient and bring down the next digit. For example, in 1008 ÷ 4: 4 goes into 10 twice (8), remainder 2. Bring down 0 to get 20. 4 goes into 20 five times (20). Bring down 8. 4 goes into 8 twice. Answer: 252.

Can long division result in a fraction?

Yes. Any division can be expressed as a fraction: dividend/divisor. For example, 125 ÷ 8 can be written as 125/8, which equals 15 5/8 as a mixed number. The remainder becomes the numerator of the fractional part.

What if the divisor is larger than any single digit of the dividend?

Look at more digits together. For example, in 2847 ÷ 23, you can't divide 23 into 2, so you look at 28 instead. 23 fits into 28 once. Then continue the process with the remaining digits.

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Long Division Calculator FAQ

What is long division?

Long division is a method for dividing large numbers by breaking the problem into a series of smaller, easier steps. It involves repeatedly dividing, multiplying, and subtracting until no digits remain, producing a quotient and possibly a remainder.

How do you do long division step by step?

Long division follows four repeating steps: (1) Divide—determine how many times the divisor fits into the current portion of the dividend; (2) Multiply—multiply the divisor by that number; (3) Subtract—subtract the product from the current portion; (4) Bring down—bring down the next digit and repeat until no digits remain.

What is the difference between quotient and remainder?

The quotient is the main answer to a division problem—how many whole times the divisor fits into the dividend. The remainder is what's left over after the division is complete, representing the portion of the dividend that cannot be evenly divided.

How do you check if a long division answer is correct?

Multiply the quotient by the divisor, then add the remainder. The result should equal the original dividend. Formula: (Quotient × Divisor) + Remainder = Dividend. For example, 125 ÷ 8 = 15 R 5 can be verified: (15 × 8) + 5 = 120 + 5 = 125.

What happens when the dividend is smaller than the divisor?

When the dividend is smaller than the divisor, the quotient is 0 and the remainder equals the dividend. For example, 5 ÷ 8 = 0 remainder 5, because 8 does not fit into 5 at all.

Can you do long division with decimals?

Yes. To continue dividing past the remainder, add a decimal point to the quotient and zeros to the remainder, then continue the division process. For example, 125 ÷ 8 = 15.625 when carried out to three decimal places.

Why is long division important to learn?

Long division builds foundational understanding of how division works and develops number sense. It's essential for polynomial division in algebra, understanding ratios and proportions, and working with fractions. The systematic approach also strengthens problem-solving skills.

What is the difference between long division and short division?

Short division is a condensed form where intermediate calculations are done mentally and only the quotient is written. Long division writes out every step explicitly, making it easier to follow and learn from, especially with larger numbers.

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