➗ 1C | Long Division Study Guide

Unit 1: Number Sense • Lessons 1.7–1.9 • Standard: 6.NOS.2

📘 Key Vocabulary

Dividend — the number being divided (the number inside or under the division bracket). (dividendo)
Divisor — the number you divide by (the number outside the bracket). (divisor)
Quotient — the answer to a division problem. (cociente)
Remainder — the amount left over when a number does not divide evenly. (residuo / resto)

📋 Visual Example — Parts of a Division Problem

        quotient
        --------
divisor | dividend

         39
       ------
  12 ) 468

468 ÷ 12 = 39 — The dividend is 468, the divisor is 12, the quotient is 39.

🔢 Step-by-Step — DMSB Method

Remember: Divide → Multiply → Subtract → Bring down   (repeat!)

  1. D Divide: How many times does the divisor go into the first digits of the dividend?
  2. M Multiply: Multiply the divisor by the number you wrote on top.
  3. S Subtract: Subtract that product from the digits above.
  4. B Bring down: Bring down the next digit from the dividend.

Repeat D-M-S-B until there are no more digits to bring down.

Worked Example: 468 ÷ 12
       3 9
     ------
 12 ) 4 6 8

 Step 1 (D): 12 goes into 46 → 3 times
 Step 2 (M): 3 × 12 = 36
 Step 3 (S): 46 - 36 = 10
 Step 4 (B): Bring down 8 → 108

 Step 5 (D): 12 goes into 108 → 9 times
 Step 6 (M): 9 × 12 = 108
 Step 7 (S): 108 - 108 = 0

 No more digits. Remainder = 0.
 Answer: 468 ÷ 12 = 39

📐 Formula Box

Dividend ÷ Divisor = Quotient (+ Remainder)
Check: Quotient × Divisor + Remainder = Dividend

💡 Memory Tip

Remember DMSB with this sentence:

"Does McDonald's Serve Burgers?"

Divide → Multiply → Subtract → Bring down

⚠️ Watch Out!

✏️ Practice Problems

1. 156 ÷ 12 = ?

2. 725 ÷ 25 = ?

3. 1,344 ÷ 16 = ?

4. 2,580 ÷ 15 = ?