lenny

3-Digit Dash!

Lesson Plan

3-Digit Dash!

Students will accurately add and subtract 3-digit numbers with regrouping, demonstrating understanding of place value and inverse operations.

Mastering 3-digit addition and subtraction is crucial for developing strong number sense and is a foundational skill for more complex math concepts. This lesson helps students overcome challenges with regrouping, boosting their confidence and accuracy.

Audience

3rd Grade Students (Tier 2 Small Group)

Time

30 minutes

Approach

Through guided practice and a fun activity, students will reinforce 3-digit addition and subtraction skills.

Materials

Whiteboard or projector, Dry-erase markers, 3-Digit Dash! Slide Deck, Warm-Up: Regrouping Readiness, Worksheet: Operation Orbit, Answer Key: Operation Orbit, and Cool Down: Quick Check

Prep

Teacher Preparation

10 minutes

Step 1

Warm-Up & Introduction (5 minutes)

5 minutes

Step 2

Guided Practice: Addition (10 minutes)

10 minutes

  • Use Slides 3-5 of the 3-Digit Dash! Slide Deck to guide students through 3-digit addition with regrouping.
    - Work through examples step-by-step, emphasizing place value and the regrouping process.
    - Encourage students to explain their thinking and ask questions.

Step 3

Guided Practice: Subtraction (10 minutes)

10 minutes

  • Transition to 3-digit subtraction with regrouping using Slides 6-8 of the 3-Digit Dash! Slide Deck.
    - Model examples, focusing on 'borrowing' and how it relates to regrouping.
    - Provide opportunities for students to try problems independently with support.
    - Distribute the Worksheet: Operation Orbit for independent or small group practice, allowing students to start on it during this time if they finish the guided practice quickly.

Step 4

Wrap-Up & Cool Down (5 minutes)

5 minutes

  • Briefly review key strategies for addition and subtraction with regrouping.
    - Have students complete the Cool Down: Quick Check as an exit ticket.
    - Collect worksheets and cool-downs for assessment, using the Answer Key: Operation Orbit for reference.
lenny
0 educators
use Lenny to create lessons.

No credit card needed

Slide Deck

Welcome to 3-Digit Dash!

Ready to become a math master with BIG numbers?

Today, we'll conquer 3-digit addition and subtraction!

Greet students and introduce the exciting journey we're about to embark on into 3-digit numbers! Explain that these skills are like superpowers for solving bigger math problems in real life.

Why is this important?

It helps you solve real-world problems like:

  • How many points did two teams score together?
  • How much change will you get back from a purchase?
  • Planning a trip by calculating distances!

It's all about becoming a number detective!

Explain that 'regrouping' is like trading smaller pieces for bigger ones, or vice versa, to make problems easier. It's crucial for both addition and subtraction.

Adding with Regrouping: Let's Go!

Remember our place value: Hundreds, Tens, Ones.

When we add and get more than 9 in a place, we 'regroup' to the next place value.

Introduce the concept of 3-digit addition with regrouping. Emphasize starting from the ones place.

Example 1: Let's Add!

145 + 237

  1. Add the Ones: 5 + 7 = 12 (Regroup the 10 ones as 1 ten)
  2. Add the Tens: 4 + 3 + 1 (regrouped ten) = 8
  3. Add the Hundreds: 1 + 2 = 3

Answer: 382

Guide students through the first example, asking them to participate step-by-step. Use a visual aid or model on a whiteboard.

Your Turn! Addition Practice

368 + 154

Think about:

  • Where do you start?
  • When do you regroup?
  • What's your final answer?





Present another example for students to try. Walk them through it, providing support as needed. Encourage them to explain their steps.

Subtracting with Regrouping: Take It Away!

Sometimes, you don't have enough in a place value to subtract.

No worries! You can 'regroup' or 'borrow' from the next place value over.

Transition to subtraction with regrouping. Explain that it's similar to addition, but we sometimes 'borrow' from the next place value.

Example 1: Let's Subtract!

452 - 128

  1. Subtract the Ones: Can't do 2 - 8! Regroup 1 ten from the 5 tens (4 tens left, 12 ones now)
  2. Subtract the Ones: 12 - 8 = 4
  3. Subtract the Tens: 4 - 2 = 2
  4. Subtract the Hundreds: 4 - 1 = 3

Answer: 324

Guide students through the first subtraction example. Emphasize the borrowing process and how it changes the numbers.

Your Turn! Subtraction Practice

531 - 219

Remember to:

  • Start from the ones!
  • Regroup when needed.
  • Check your work!





Present another subtraction example for students to try, again encouraging them to articulate their steps.

You're a 3-Digit Master!

Today we learned to:

  • Add 3-digit numbers with regrouping.
  • Subtract 3-digit numbers with regrouping.

Keep practicing your math superpowers!

Quickly review the main points. Ask students if they have any lingering questions. Distribute the cool-down.

lenny

Warm Up

Warm-Up: Regrouping Readiness!

Instructions: Solve the following problems. If you need to regroup, show your work!

  1. 35 + 8


  2. 61 - 7


  3. 123 + 9


  4. 40 - 5


lenny
lenny

Worksheet

Worksheet: Operation Orbit

Instructions: Launch into these 3-digit problems! Show your work for each one.

Addition Astronauts

  1. 247 + 135





  2. 389 + 214





  3. 506 + 297





  4. 172 + 658





Subtraction Superheroes

  1. 463 - 128





  2. 725 - 319





  3. 800 - 451





  4. 910 - 307





lenny
lenny

Answer Key

Answer Key: Operation Orbit

Addition Astronauts

  1. 247 + 135

    • Step 1 (Ones): 7 + 5 = 12. Write down 2, regroup 1 ten to the tens place.
    • Step 2 (Tens): 4 + 3 + 1 (regrouped ten) = 8. Write down 8.
    • Step 3 (Hundreds): 2 + 1 = 3. Write down 3.
    • Answer: 382

  2. 389 + 214

    • Step 1 (Ones): 9 + 4 = 13. Write down 3, regroup 1 ten to the tens place.
    • Step 2 (Tens): 8 + 1 + 1 (regrouped ten) = 10. Write down 0, regroup 1 hundred to the hundreds place.
    • Step 3 (Hundreds): 3 + 2 + 1 (regrouped hundred) = 6. Write down 6.
    • Answer: 603

  3. 506 + 297

    • Step 1 (Ones): 6 + 7 = 13. Write down 3, regroup 1 ten to the tens place.
    • Step 2 (Tens): 0 + 9 + 1 (regrouped ten) = 10. Write down 0, regroup 1 hundred to the hundreds place.
    • Step 3 (Hundreds): 5 + 2 + 1 (regrouped hundred) = 8. Write down 8.
    • Answer: 803

  4. 172 + 658

    • Step 1 (Ones): 2 + 8 = 10. Write down 0, regroup 1 ten to the tens place.
    • Step 2 (Tens): 7 + 5 + 1 (regrouped ten) = 13. Write down 3, regroup 1 hundred to the hundreds place.
    • Step 3 (Hundreds): 1 + 6 + 1 (regrouped hundred) = 8. Write down 8.
    • Answer: 830

Subtraction Superheroes

  1. 463 - 128

    • Step 1 (Ones): Can't subtract 8 from 3. Regroup 1 ten from the tens place (6 tens becomes 5 tens, 3 ones becomes 13 ones). Now 13 - 8 = 5. Write down 5.
    • Step 2 (Tens): 5 (new tens) - 2 = 3. Write down 3.
    • Step 3 (Hundreds): 4 - 1 = 3. Write down 3.
    • Answer: 335

  2. 725 - 319

    • Step 1 (Ones): Can't subtract 9 from 5. Regroup 1 ten from the tens place (2 tens becomes 1 ten, 5 ones becomes 15 ones). Now 15 - 9 = 6. Write down 6.
    • Step 2 (Tens): 1 (new tens) - 1 = 0. Write down 0.
    • Step 3 (Hundreds): 7 - 3 = 4. Write down 4.
    • Answer: 406

  3. 800 - 451

    • Step 1 (Ones): Can't subtract 1 from 0. Go to the tens place, but it's also 0. Regroup 1 hundred from the hundreds place (8 hundreds becomes 7 hundreds, 0 tens becomes 10 tens). Now regroup 1 ten from the 10 tens (10 tens becomes 9 tens, 0 ones becomes 10 ones). Now 10 - 1 = 9. Write down 9.
    • Step 2 (Tens): 9 (new tens) - 5 = 4. Write down 4.
    • Step 3 (Hundreds): 7 (new hundreds) - 4 = 3. Write down 3.
    • Answer: 349

  4. 910 - 307

    • Step 1 (Ones): Can't subtract 7 from 0. Regroup 1 ten from the tens place (1 ten becomes 0 tens, 0 ones becomes 10 ones). Now 10 - 7 = 3. Write down 3.
    • Step 2 (Tens): 0 (new tens) - 0 = 0. Write down 0.
    • Step 3 (Hundreds): 9 - 3 = 6. Write down 6.
    • Answer: 603
lenny
lenny

Cool Down

Cool Down: Quick Check

Instructions: Show what you know! Solve these two problems.

  1. 348 + 175


  2. 605 - 231


Bonus Question: What was one new thing you learned or remembered about regrouping today?





lenny
lenny
3-Digit Dash! • Lenny Learning