Practice Set · Part 1
Divide Multi-Digit Numbers Using an Algorithm
Pick up where we left off
Where we left off
Our goal: I can divide multi-digit whole numbers and explain the meaning of the quotient and remainder, explain why the method works, and use it on a problem I have not seen before.
The big idea: The quotient tells how many equal groups, and the remainder tells what is left. The question decides if you drop the remainder or add one more group.
Model to copy — Example · What does the remainder mean?
- 1,350 students go on a trip. Each bus holds 48 students. How many buses are needed?
- Divide 135 by 48. Multiply and subtract: 135 ÷ 48 → 2; 2 × 48 = 96; 135 − 96 = 39
- Bring down the 0. Divide 390 by 48: 390 ÷ 48 → 8; 8 × 48 = 384; 390 − 384 = 6
- Write the quotient and the remainder: 1,350 ÷ 48 → 28 R 6
- Decide what the remainder means: 28 full buses + 6 students
- 29 buses are needed. 28 buses are full, and 1 more bus carries the last 6 students.
Start here
Use the model to solve the first problem. Then try these quick review questions from earlier lessons.
- 1
Same stepsFinish what the group started. Use the model above, step for step.
Try it together — then prove it:- Find 384 ÷ 8.
- Divide 38 by 8. Then multiply and subtract. (4 on top. 4 × 8 = 32, and 38 − 32 = 6)
- Bring down the 4. Divide, multiply and subtract again. (8 on top. 8 × 8 = 64, and 64 − 64 = 0)
- After you subtract, why must the result be less than 8? (If it were 8 or more, another 8 would still fit. Then the digit on top would be too small.)
Show your work - 2
Quick reviewWhat is 7 × 40?
- A28
- B47
- C280
- D2,800
How do you know?
- 3
Quick reviewWhat is 96 ÷ 8?
- A8
- B11
- C12
- D14
How do you know?
- 4
Quick reviewWhich multiplication fact helps you divide 200 by 5?
- A5 × 40 = 200
- B5 × 20 = 100
- C5 × 4 = 20
- D5 × 50 = 250
How do you know?
Practice Set · Part 2
Divide Multi-Digit Numbers Using an Algorithm
Keep going
Try these on your own
Choose an answer. Then explain how you know.
- 5
Think it through1,680 ÷ 24 = ?
- A60
- B70
- C72
- D80
Why is that the answer?
- 6
Think it throughEstimate first: rounding to 1,600 ÷ 20 gives about how many pencils per room?
- A40
- B60
- C80
- D100
How do you know? Give a second reason as well.
- 7
Think it throughIf the pencils were split among 20 classrooms instead of 24, would each room get more or fewer?
- AFewer, because 20 is less than 24
- BThe same, because the total did not change
- CMore, because the pencils are split among fewer rooms
- DYou cannot tell
Explain your thinking. What would have to change for a different choice to be right?
- 8
Back to the modelYou ran the cycle 3 times. What is 3,822 ÷ 14, and how did you know when to stop repeating divide, multiply, subtract, bring down?
Practice Set · Part 3
Divide Multi-Digit Numbers Using an Algorithm
Words and reasoning
Word bank · Banco de palabras
Use the words
Fill each blank with a word from the bank.
- In 84 ÷ 7, the number 84 being divided is the ___.
- In 84 ÷ 7, the number 7 that we divide by is the ___.
- The answer to a division problem is called the ___.
- When a number does not divide evenly, the amount left over is the ___.
Explain the thinking
- 9
Find the mistakeRead the mistake. Explain what went wrong, then show the correct step.
The mistake: A common mistake in Divide Multi-Digit Numbers is skipping a placeholder zero in the quotient when a digit doesn't divide evenly, which shifts every digit after it out of place. - 10
Say moreYou used long division for 1,344 ÷ 12. Walk through your divide, multiply, subtract, and bring down steps — what did each one tell you?
- 11
Write your ownWrite your own problem about this situation, then solve it and show the answer. The situation: A school district has 13,275 elementary-age students. The district plans to redistrict and divide the students equally among its 15 elementary schools.
Show your work
Practice Set · Part 4
Divide Multi-Digit Numbers Using an Algorithm
Show what you know
Last check
These two come from Lesson 2.5. If they are shaky, that is the lesson to revisit — not this one.
- 12
Show what you knowExplain your thinking — What is 2,352 ÷ 16?
- A137
- B146
- C147
- D157
Explain your choice.
- 13
From Lesson 2.5Explain your thinking — A box plot has Q1 = 20 and Q3 = 36, with a least value of 10 and a greatest value of 50. What is the IQR, and what does it tell you?
- AIQR = 16; the middle half of the data spans 16 units
- BIQR = 28; 28 is halfway between the quartiles
- CIQR = 40; the data spans 40 units from end to end
- DIQR = 56; the quartiles add to 56
How do you know?
- 14
From Lesson 2.5Both classes have a median of 81. What do the smaller range and smaller IQR tell you about Class B?
- AClass B's best score was higher
- BClass B had fewer students
- CClass B's median is actually larger
- DClass B's scores are less spread out, so more students scored near the median
How do you know?
Check your progress
Choose the box that best describes how you feel about each skill.
| I can… | Not yet | Getting there | Got it |
|---|---|---|---|
| I can divide multi-digit whole numbers and explain the meaning of the quotient and remainder, explain why the method works, and use it on a problem I have not seen before. | |||
| I can explain why it works: The quotient tells how many equal groups, and the remainder tells what is left… | |||
| I can justify my answer to a skeptic and connect it to a second strategy or representation. |
One question I want to ask my group next time