M6MATH-4.1

Dividing Multi-Digit Whole Numbers

Learn how to divide multi-digit whole numbers using long division, and verify answers by multiplying back with the divisor—an essential skill for working with larger numbers.

What you'll do in this lesson

A voice-first session with the Crimsora tutor on Dividing Multi-Digit Whole Numbers, then targeted practice and FRQs — with the tutor adapting to where you get stuck.

What this lesson covers

Division becomes much more powerful when you can tackle numbers that don't divide evenly in your head. In Grade 5, you probably divided smaller numbers or used division facts. Now you'll learn the standard long-division algorithm that works for any multi-digit whole number, and you'll discover how to check your work using multiplication. This skill is the foundation for dividing decimals later on, and it builds your confidence with all kinds of real-world problems—from sharing amounts fairly to measuring how many times one quantity fits into another.

Understanding Division with Remainders

When you divide one whole number by another, you may not get a whole number answer. Instead, you get a quotient (the main answer) and sometimes a remainder (what's left over). For example, 27÷5=527 \div 5 = 5 remainder 22, because 5×5=255 \times 5 = 25, and 2725=227 - 25 = 2 is what's left. You can write this as 27÷5=5 R227 \div 5 = 5\text{ R}2 or as 5255\frac{2}{5} (five and two-fifths). The remainder is always smaller than the divisor—if your remainder is bigger, you didn't divide enough times.

With multi-digit numbers, remainders work the same way. If you divide 348348 by 66, you're asking: how many groups of 66 fit into 348348? The answer is 5858 groups with a remainder of 00 (since 6×58=3486 \times 58 = 348). The key insight is that the process stays the same whether you're dividing small or large numbers—you just repeat the steps more times.

The Long-Division Algorithm

Long division breaks the problem into smaller, manageable steps. You divide one digit (or group of digits) at a time, starting from the left.

Here's the repeating pattern: divide, multiply, subtract, bring down.

Start by looking at just the leftmost digits of the dividend until you have a number that the divisor goes into at least once. Divide that group by the divisor and write the quotient digit above. Multiply the quotient digit by the divisor and write the result below the digits you were dividing. Subtract to find what's left. Bring down the next digit and repeat.

For example, to divide 456÷12456 \div 12:

The divisor 1212 doesn't fit into 44, so look at 4545. Twelve goes into 4545 three times (12×3=3612 \times 3 = 36). Write 33 above the 55. Subtract: 4536=945 - 36 = 9. Bring down the 66 to make 9696. Twelve goes into 9696 eight times (12×8=9612 \times 8 = 96). Write 88 above the 66. Subtract: 9696=096 - 96 = 0. Your quotient is 3838 with no remainder.

When you reach the last digit and have a number smaller than the divisor, that becomes your remainder.

Checking Your Answer with Multiplication

The best way to verify division is to reverse it: multiply the quotient by the divisor and add the remainder. If this equals the original dividend, you're correct.

The relationship is: (Quotient×Divisor)+Remainder=Dividend\text{(Quotient} \times \text{Divisor)} + \text{Remainder} = \text{Dividend}

For the example above, 456÷12=38456 \div 12 = 38 with remainder 00. Check: (38×12)+0=456+0=456(38 \times 12) + 0 = 456 + 0 = 456. ✓

If you had divided incorrectly and gotten quotient 3737, your check would show: (37×12)+R=444+R=456(37 \times 12) + \text{R} = 444 + \text{R} = 456, so R=12\text{R} = 12. But a remainder can never be as large as the divisor, so you'd know something went wrong and could find the error.

This check is your safety net. Always multiply back; it takes just a few seconds and catches mistakes immediately.

Common Mistakes and How to Avoid Them

One frequent error is forgetting to bring down the next digit. After you subtract, you must bring down the very next digit from the dividend before dividing again. If you skip this step, your quotient will be way too small.

Another common mistake is writing the quotient digit in the wrong place. The quotient digit you write goes directly above the last digit of the group you just divided. If you move one place left or right, your final answer shifts by a power of ten.

Students also sometimes give a remainder that's larger than or equal to the divisor. Remember: if your remainder is 1212 and your divisor is 1212, you can divide one more time. Keep dividing until the remaining number is smaller than the divisor.

Finally, be careful with zeros in the quotient. If the divisor doesn't fit into the next group of digits, you must write a 00 in the quotient (in the correct place) and bring down another digit. Skipping the zero will misalign everything that comes after.

Why This Matters Beyond Division

The long-division algorithm is not just about dividing whole numbers. It's the foundation for dividing decimals, which you'll learn soon. When you divide decimals, the process is identical—you just have to place the decimal point correctly in your answer. Understanding how and why long division works now means you won't struggle with decimals later.

Division also connects directly to fractions and ratios. When you divide to get a remainder and convert it into a fraction, you're building fraction sense. And in real situations—figuring out how many buses you need to transport students, calculating unit prices, or sharing amounts fairly—division with remainders is exactly what you need.

Key terms

Dividend.
The number being divided. In 456÷12456 \div 12, the dividend is 456456.
Divisor.
The number you are dividing by. In 456÷12456 \div 12, the divisor is 1212.
Quotient.
The result of division (the answer before the remainder). In 456÷12=38456 \div 12 = 38, the quotient is 3838.
Remainder.
The amount left over after division when it doesn't divide evenly. In 27÷5=5 R227 \div 5 = 5\text{ R}2, the remainder is 22.
Long division.
A step-by-step algorithm for dividing multi-digit numbers: divide, multiply, subtract, and bring down.
Verify or check.
To confirm an answer is correct, usually by performing the inverse operation (multiplication, in the case of division).

Worked example

Divide 738÷15738 \div 15 and check your answer.
Step 1: Set up long division. Write 738738 inside the division bracket and 1515 outside to the left.

Step 2: Find where to start. Does 1515 go into 77? No. Does 1515 go into 7373? Yes. Fifteen goes into 7373 four times, because 15×4=6015 \times 4 = 60. Write 44 above the 33 in the quotient line.

Step 3: Multiply and subtract. Multiply: 15×4=6015 \times 4 = 60. Subtract: 7360=1373 - 60 = 13. Write 1313 below.

Step 4: Bring down the next digit. Bring down the 88 to make 138138.

Step 5: Divide again. How many times does 1515 go into 138138? Try 99: 15×9=13515 \times 9 = 135. Yes, that works. Write 99 above the 88 in the quotient line.

Step 6: Multiply and subtract. Multiply: 15×9=13515 \times 9 = 135. Subtract: 138135=3138 - 135 = 3. Write 33 below.

Step 7: Check the remainder. Is 33 smaller than 1515 (the divisor)? Yes. So you're done. The quotient is 4949 with remainder 33, written as 49 R349\text{ R}3.

Step 8: Verify. Use the check formula: (Quotient×Divisor)+Remainder=Dividend(\text{Quotient} \times \text{Divisor}) + \text{Remainder} = \text{Dividend}. (49×15)+3=735+3=738(49 \times 15) + 3 = 735 + 3 = 738. ✓ Correct!

Practice questions

Divide 624÷16624 \div 16 using long division and verify your answer.

Answer: The quotient is 3939 with remainder 00. Check: (39×16)+0=624(39 \times 16) + 0 = 624. ✓

Start by asking: does 1616 go into 66? No. Does 1616 go into 6262? Yes, 33 times (16×3=4816 \times 3 = 48). Subtract: 6248=1462 - 48 = 14. Bring down the 44 to make 144144. Does 1616 go into 144144? Yes, 99 times (16×9=14416 \times 9 = 144). Subtract: 144144=0144 - 144 = 0. Since the remainder is 00, we write 3939 with no remainder. To check, multiply 39×16=62439 \times 16 = 624, which matches the dividend.
A teacher has 856856 pencils to share equally among 1212 students. How many pencils does each student get, and how many are left over?

Answer: Each student gets 7171 pencils, and 44 pencils are left over.

This is a division problem: 856÷12856 \div 12. Using long division: 1212 goes into 8585 seven times (12×7=8412 \times 7 = 84). Subtract to get 11. Bring down the 66 to make 1616. Twelve goes into 1616 once (12×1=1212 \times 1 = 12). Subtract: 1612=416 - 12 = 4. The quotient is 7171 with remainder 44, which means each of the 1212 students receives 7171 pencils and 44 are left over. You can verify: (71×12)+4=852+4=856(71 \times 12) + 4 = 852 + 4 = 856. ✓
Divide 2045÷232045 \div 23. What is the quotient?
  1. 87 R2487\text{ R}24
  2. 8989
  3. 89 R889\text{ R}8
  4. 88 R2188\text{ R}21

Answer: 8989

Using long division: 2323 doesn't go into 2020, so look at 204204. Twenty-three goes into 204204 eight times (23×8=18423 \times 8 = 184). Subtract: 204184=20204 - 184 = 20. Bring down the 55 to make 205205. Twenty-three goes into 205205 eight times... wait, let me recalculate. 23×9=20723 \times 9 = 207, which is too large. 23×8=18423 \times 8 = 184. Actually, 23×9=20723 \times 9 = 207, which exceeds 205205. Let me redo: 204204 divided by 2323: try 88. 23×8=18423 \times 8 = 184. Subtract: 204184=20204 - 184 = 20. Bring down the 55 to make 205205. Now, 23×8=18423 \times 8 = 184 (too small) and 23×9=20723 \times 9 = 207 (too large for 205205). Actually 23×9=207>20523 \times 9 = 207 > 205, so use 88. Wait: 23×9=20723 \times 9 = 207, and 205<207205 < 207, so we use 88. 205184=21205 - 184 = 21... Let me recalculate fully. 2045÷232045 \div 23: Try 8989. Check: 89×23=(901)×23=207023=204789 \times 23 = (90 - 1) \times 23 = 2070 - 23 = 2047. That's too large. Try 8888. 88×23=(902)×23=207046=202488 \times 23 = (90 - 2) \times 23 = 2070 - 46 = 2024. Subtract: 20452024=212045 - 2024 = 21. So the answer is 88 R2188\text{ R}21. But that's option D. Let me recheck the problem... Actually, 89×2389 \times 23: 89×20=178089 \times 20 = 1780, 89×3=26789 \times 3 = 267. Total: 1780+267=20471780 + 267 = 2047. That exceeds 20452045. Using 8888: 88×23=202488 \times 23 = 2024. Remainder: 20452024=212045 - 2024 = 21. The correct answer is 88 R2188\text{ R}21, which is choice D. However, the question states the answer should be 8989, which doesn't match. Let me verify once more: if the answer really is 8989, then 89×2389 \times 23 should be close to 20452045. It equals 20472047, which is 22 more than 20452045. So 8989 is too large. The correct answer should be option D: 88 R2188\text{ R}21. There appears to be an error in the question as stated. For the purposes of this guide, the correct quotient is 88 R2188\text{ R}21.

FAQ

What do I do if the divisor doesn't fit into the first digit of the dividend?
Look at the first two digits instead. If the divisor still doesn't fit, look at the first three digits. Keep combining digits from the left until you have a number that the divisor can go into at least once. Make sure to write the first digit of your quotient above the correct place—above the last digit of the group you just divided.
How do I know when to write a zero in the quotient?
Write a zero in the quotient when the divisor doesn't fit into the number you brought down. For example, if you bring down a digit and now have 1515, but your divisor is 2323, you can't divide. Write a 00 in the quotient (in the correct position) and bring down the next digit. This keeps your quotient aligned correctly.
My remainder is bigger than the divisor. What did I do wrong?
You didn't divide enough times. If your remainder is larger than the divisor, that means the divisor fits into it at least once more. Go back and increase your quotient digit, then redo the multiplication and subtraction. Keep dividing until the remainder is smaller than the divisor.
Why do I need to check my division by multiplying?
Multiplication is the inverse (opposite) of division. When you multiply the quotient by the divisor and add the remainder, you should get back the original dividend. If you don't, you made a mistake somewhere in the long division. Checking catches errors early so you can fix them before moving on.

Learn this with a teacher, not a page

The Crimsora tutor teaches Dividing Multi-Digit Whole Numbers live — explaining on a whiteboard, asking you questions, and adapting to where you get stuck.