Long Division Algorithm | Lesson 1 of 2

Master Long Division With Multi-Digit Numbers

In this lesson:

  • Read each quotient digit as a place-value amount
  • Run the four-move cycle: divide, multiply, subtract, bring down
  • Estimate two-digit-divisor quotients and adjust by one
Grade 6 Mathematics | Standard 6.NS.B.2
Long Division Algorithm | Lesson 1 of 2

What You Will Be Able to Do

By the end, you will:

  1. Run the four moves: divide, multiply, subtract, bring down
  2. Read each quotient digit in place-value language
  3. Predict the quotient's digit count first
  4. Estimate two-digit-divisor digits and adjust
  5. Place a zero in the quotient when the divisor doesn't fit
Grade 6 Mathematics | Standard 6.NS.B.2
Long Division Algorithm | Lesson 1 of 2

A Familiar Case to Read Aloud

Read the quotient digits in place-value language:

  • The 2 above the 8 means 2 tens
  • The 1 above the 4 means 1 one
  • Together:
Grade 6 Mathematics | Standard 6.NS.B.2
Long Division Algorithm | Lesson 1 of 2

Each Quotient Digit Names a Place Value

A long-division layout for 1,536 divided by 4 with the quotient 384 written above; vertical guides connect the 3 to the hundreds column of the dividend, the 8 to the tens column, the 4 to the ones column; each quotient digit is labeled with its place-value meaning hundreds, tens, ones; below the layout the equation 300 + 80 + 4 = 384 is written

Each digit's column tells you its place value.

Grade 6 Mathematics | Standard 6.NS.B.2
Long Division Algorithm | Lesson 1 of 2

The Four Moves of Long Division

Each cycle has four steps that repeat:

  1. Divide — how many divisors fit into the partial dividend?
  2. Multiply — that many times the divisor
  3. Subtract — from the partial dividend
  4. Bring down — the next digit of the dividend

The cycle repeats until the dividend is exhausted.

Grade 6 Mathematics | Standard 6.NS.B.2
Long Division Algorithm | Lesson 1 of 2

Walking Through 1,536 Divided by 4

How many 4s in 15 hundreds? 3 hundreds, leftover 3 hundreds.

Bring down 3 tens → 33 tens. How many 4s? 8 tens, leftover 1 ten.

Bring down 6 ones → 16 ones. How many 4s? 4 ones, exactly.

Grade 6 Mathematics | Standard 6.NS.B.2
Long Division Algorithm | Lesson 1 of 2

When the Divisor Doesn't Fit Yet

In , the leftmost digit is 1, but 4 doesn't fit into 1.

  • Look at the first two digits together: 15
  • The first quotient digit lands above the hundreds column, not thousands

This is normal — not an error.

Grade 6 Mathematics | Standard 6.NS.B.2
Long Division Algorithm | Lesson 1 of 2

Worked Example: 2,940 Divided by 5

How many 5s in 29 hundreds? 5 hundreds, leftover 4 hundreds.

Bring down 4 tens → 44 tens. How many 5s? 8 tens, leftover 4 tens.

Bring down 0 ones → 40 ones. How many 5s? 8 ones.

Grade 6 Mathematics | Standard 6.NS.B.2
Long Division Algorithm | Lesson 1 of 2

Watch Out: Place a Zero, Don't Skip

Two long-division layouts side by side for 6,003 ÷ 3; left layout WRONG shows quotient 21 with the divisor skipping over the inner zeros; right layout RIGHT shows quotient 2,001 with two zeros placed in the tens and hundreds columns; a red X over the wrong layout, a green check over the right layout

Every position contributes a digit — write the 0 when the divisor doesn't fit.

Grade 6 Mathematics | Standard 6.NS.B.2
Long Division Algorithm | Lesson 1 of 2

Worked Example: 6,003 Divided by 3

How many 3s in 6 thousands? 2 thousands, exactly.

How many 3s in 0 hundreds? 0 hundreds — write the zero.

How many 3s in 0 tens? 0 tens — write the zero.

How many 3s in 3 ones? 1 one.

Grade 6 Mathematics | Standard 6.NS.B.2
Long Division Algorithm | Lesson 1 of 2

Two-Digit Divisors Need an Estimate

For one-digit divisors, multiplication facts give the answer.

For two-digit divisors, no fact applies — you must estimate.

Grade 6 Mathematics | Standard 6.NS.B.2
Long Division Algorithm | Lesson 1 of 2

Predict the Quotient's Digit Count First

Before dividing :

  • Dividend has 4 digits; divisor has 2 digits
  • Quotient has either 2 or 3 digits

This catches missing-zero errors before they happen.

Grade 6 Mathematics | Standard 6.NS.B.2
Long Division Algorithm | Lesson 1 of 2

Round the Divisor to Estimate

To estimate "how many 24s in 187":

Round to a friendlier number, multiply, see how close.

Grade 6 Mathematics | Standard 6.NS.B.2
Long Division Algorithm | Lesson 1 of 2

Worked Example: 1,872 Divided by 24

24 doesn't fit into 1 or 18 — look at 187.

Estimate: , try 7. . .

Bring down 2 → 192. exactly. Write 8.

Grade 6 Mathematics | Standard 6.NS.B.2
Long Division Algorithm | Lesson 1 of 2

When the Estimate Is Too High: Adjust Down

A two-column comparison card titled Estimate Too High; left column shows the trial 24 × 8 = 192 with 192 > 187 marked in red; right column shows the adjusted trial 24 × 7 = 168 with 168 ≤ 187 marked in green; a small arrow between columns labeled minus 1

Product bigger than partial dividend? Reduce the estimate by 1.

Grade 6 Mathematics | Standard 6.NS.B.2
Long Division Algorithm | Lesson 1 of 2

When the Estimate Is Too Low: Adjust Up

Suppose you tried 6:

But — leftover is too big. Increase by 1.

Grade 6 Mathematics | Standard 6.NS.B.2
Long Division Algorithm | Lesson 1 of 2

Try, Multiply, Check, Adjust

The loop:

  1. Try a digit (rounded-divisor estimate)
  2. Multiply divisor × digit
  3. Check — fits under the partial dividend? Leftover < divisor?
  4. Adjust by ±1 if needed

Expect to miss sometimes. The loop handles it.

Grade 6 Mathematics | Standard 6.NS.B.2
Long Division Algorithm | Lesson 1 of 2

Worked Example: 7,488 Divided by 36

Predict: 4-digit ÷ 2-digit → quotient has 3 or 4 digits.

36 fits into 74 → 2 times (, leftover 2).

Bring down 8 → 28. 36 doesn't fit → write 0.

Bring down 8 → 288. → write 8.

Grade 6 Mathematics | Standard 6.NS.B.2
Long Division Algorithm | Lesson 1 of 2

Check-In: Compute and Predict First

Before dividing, predict the quotient's digit count, then compute:

Show your prediction, then your work.

Grade 6 Mathematics | Standard 6.NS.B.2
Long Division Algorithm | Lesson 1 of 2

Answers and Common Errors to Avoid

  1. (3 digits ✓)
  2. (3 digits ✓)

⚠️ Wrong answer 65 on Q1 → dropped a digit somewhere.

⚠️ Wrong answer 26 on Q2 → missing-zero or alignment error.

Grade 6 Mathematics | Standard 6.NS.B.2
Long Division Algorithm | Lesson 1 of 2

Key Takeaways for Long Division

  • Every quotient digit names a place-value amount
  • The four moves cycle: divide, multiply, subtract, bring down
  • Predict the quotient's digit count first
  • Two-digit divisors need an estimate; adjust by ±1
  • Place a zero when the divisor doesn't fit — don't skip
Grade 6 Mathematics | Standard 6.NS.B.2
Long Division Algorithm | Lesson 1 of 2

Coming Up: Three Forms for the Remainder

You can now run the algorithm cleanly.

In Lesson 2, you will:

  • Express a remainder in three equivalent forms
  • Choose the form a real-world question demands
  • Apply long division to bus-loading, money, sharing problems
Grade 6 Mathematics | Standard 6.NS.B.2

Click to begin the narrated lesson

Fluently divide multi-digit numbers using the standard algorithm