Regrouping Rescue Slides
Rescue Crew Academy
Grade 3 Math
Mission: 3-Digit Addition
The Great
Regrouping Rescue
Mastering 3-digit addition using three powerful strategies: Base-10 Blocks, Expanded Form, and the Standard Algorithm!
Let's construct some solid math skills today!
Slide 1 of 9
Our Construction Tools
Concrete to Abstract
Three Ways to Rescue the Numbers
1. Base-10 Blocks
Concrete & Pictorial: See exactly how ten ones trade up to make a brand-new ten rod!
Step 1: Visual Foundation
2. Expanded Form
Representational: Stretch out values into hundreds, tens, and ones to keep addition organized.
Step 2: Stretched Values
3. Standard Way
Abstract: Combine values using vertical math. Quick, efficient, and standard!
Step 3: Fast & Direct
Remember: 10 of any place value must move next door!
Slide 2 of 9
Strategy 1: Base-10 Blocks
Level: "I Do" (Teacher Model)
PROBLEM: 245 + 138
Trading 10 Ones for 1 Ten
When we add the ones, we get 13 ones. That is too many for the ones column!
The Rule of Ten:
Group 10 individual ones together to form 1 single ten rod. Move that new ten rod over to the Tens column!
Visual Representation
Hundreds
100 100 100
Tens
+1 New Ten!
Ones
(10 ones regrouped)
Final Answer: 383
Watch the regrouping: 13 ones → 1 ten and 3 ones remaining.
Slide 3 of 9
Strategy 1: Base-10 Blocks
Level: "We Do" (Guided Practice)
Let's Solve Together: 154 + 227
Get your physical blocks or drawing tools ready! Let's build both numbers step-by-step and watch the ones column.
1
Model Both
Draw 1 flat, 5 rods, 4 units. Then draw 2 flats, 2 rods, 7 units right below.
2
Find 10 Ones
Count the ones: 4 + 7 = 11. Lasso exactly 10 units to make a trade!
3
Rebuild & Count
Add the new rod to the tens column. What are the final totals for H, T, and O?
Hundreds: 3
Tens: 8
Ones: 1
Total: 381
Talk with your partner: Why did the tens digit go from 7 up to 8?
Slide 4 of 9
Strategy 2: Expanded Form
Level: "I Do" (Teacher Model)
PROBLEM: 362 + 154
Regrouping in the Tens Column
Now we expand each number to see its true values. When we add the tens, we get 110! Let's break that down.
Where does the 100 go?
Since 110 has 1 hundred and 1 ten, we send the 100 over to join the hundreds column rescue squad!
Stretched Calculation
362 = 300 + 60 + 2
+ 154 = 100 + 50 + 4
Totals = 400 + 110 + 6
Regroup = (400 + 100) + 10 + 6
Final = 500 + 10 + 6 = 516
Breaking numbers down helps us understand the secret values hidden in regrouping!
Slide 5 of 9
Strategy 2: Expanded Form
Level: "We Do" (Guided Practice)
Let's Stretch & Solve: 473 + 241
Write this on your whiteboard. Stretch both numbers into expanded form, then add each place value column!
Your Board Guide
- 1 Expand 473 → 400 + 70 + 3
- 2 Expand 241 → 200 + 40 + 1
- 3 Add Columns → 600 + 110 + 4
- 4 Regroup → 700 + 10 + 4 = 714
Check Your Grouping
Where did the 100 extra in the tens column go?
It joined the 600 to make 700!
Look at that structural logic! The values are completely clear.
Slide 6 of 9
Strategy 3: Standard Algorithm
Level: "I Do" (Teacher Model)
PROBLEM: 528 + 143
The Classic Standard Way
Now we write the numbers vertically. Keep columns strictly lined up! Add from right to left, starting with the ones.
Where to write the regrouped value?
Put the 1 ten right above the tens column. Add it in with the other tens!
Standard Setup
1
528
+143
671
Ones: 8 + 3 = 11 ones → (1 remaining, 1 regrouped to Tens)
Clean, fast, and organized. No wonder mathematicians love this algorithm!
Slide 7 of 9
Strategy 3: Standard Algorithm
Level: "We Do" (Guided Practice)
Try Vertically: 365 + 418
Line up the place values carefully. Let's process the math column by column!
Step-by-Step Questions
Ones Column: What is 5 + 8?
13 ones. Keep the 3, regroup the 1 to the Tens.
Tens Column: Don't forget the regrouped 1! What is 1 + 6 + 1?
8 tens. No regrouping needed here!
Hundreds Column: What is 3 + 4?
7 hundreds.
Board Practice
1
365
+ 418
783
Remember: Only regroup if the sum in that column is 10 or greater!
Slide 8 of 9
Independent Rescue Mission
Level: "You Do"
Time for Your Solo Missions!
Open up your Regrouping Rescue Practice Sheet. You have missions waiting for you using Base-10 Blocks, Expanded Form, and the Standard Algorithm!
Concrete Goal
Draw and circle 10 units clearly.
Expanded Goal
Stretch the values & add across.
Standard Goal
Keep columns straight, carry above.
Good luck, Rescue Crew! You are ready!
Slide 9 of 9
Regrouping Rescue Teacher Guide
Teacher Resource
Regrouping Rescue
3-Digit Addition with Single-Step Regrouping (Grade 3)
Target: Math Standard 3.NBT.A.2 Time: 60 Minutes
Lesson Objective
Students will use concrete (base-10 blocks), representational (expanded form), and abstract (standard algorithm) methods to add 3-digit numbers with single-step regrouping (regrouping once in either the ones OR tens place, but not both).
Materials & Preparation
- Regrouping Rescue Slides (for presentation)
- Base-10 Blocks (Physical flats, rods, units for student pairs)
- Student Practice Sheets & Exit Tickets
- Individual dry-erase boards and markers for "We Do" sections
Pacing Guide
| Phase | Duration | Focus & Key Activity |
|---|
| 1. Hook & Spark | 5 mins | Introduce the "Rescue Crew" theme and review value of 10. |
| 2. Strategy 1 (Concrete) | 15 mins | Base-10 model. Trade 10 units for 1 rod. (I Do / We Do) |
| 3. Strategy 2 (Rep.) | 15 mins | Expanded form. Stretching values to show column totals. |
| 4. Strategy 3 (Abstract) | 15 mins | Standard Algorithm. Vertical lining up and carrying. |
| 5. Work & Exit | 10 mins | Independent practice completion and exit ticket check. |
Common Misconceptions
The Double-Write Mistake
Students adding 8 + 3 write 11 in the ones column, writing 3211 instead of 331. Encourage drawing a "fence" between columns to limit to one digit.
The "Forgot the New Tenant" Error
Students write the regrouped "1" on top but forget to include it when adding. Ask: "Who is our new neighbor upstairs? Did we add them?"
Grade 3 Regrouping Rescue Lesson Plan Page 1 of 2
Step-by-Step Delivery
Teacher Script & Small Group Frameworks
1 Concrete Modeling (Base-10 Blocks)
Teacher Prompt: "Class, we have 13 ones in our workspace. The ones house only has room for 9 people. What can we do? Let's take exactly 10 units, put them in a cup, and trade them at the bank for 1 ten rod. See how this rod is exactly the same length? Let's move it to our tens column."
2 Representational Modeling (Expanded Form)
Regrouping Rescue Worksheet
Student Mission Sheet
Regrouping Rescue Crew
Name:
Date:
1
Strategy 1: Base-10 Blocks (Concrete)
Example (I Do): 245 + 138
Trade 10 ones for 1 ten rod.
Hundreds (H)|||
Tens (T)||||||||
Ones (O)•••
Guided (We Do): 154 + 227
Draw your blocks. Regroup 10 ones.
2
Strategy 2: Expanded Form (Representational)
Example (I Do): 362 + 154
Stretch the values to show the sums.
362 =300 + 60 + 2
+ 154 =100 + 50 + 4
Totals =400 + 110 + 6
Final =500 + 10 + 6 = 516
Guided (We Do): 473 + 241
Fill in the blanks to stretch and solve.
473 = _____ + _____ + _____
+ 241 = _____ + _____ + _____
Final = _____ + _____ + _____ = _____
Regrouping Rescue • Concrete & Representational Page 1 of 2
Standard Algorithm & Mission Goals
Strategy 3 & Your Independent Rescue Missions
3
Strategy 3: Standard Algorithm (Abstract)
Example (I Do): 528 + 143
1
528
+ 143
671
Guided (We Do): 365 + 418
365
+ 418
_ _ _
Your Turn: Independent Rescue Missions
Complete each mission using the specific tool. Show all work!
Mission A: 216 + 145 Method: Base-10 Drawings
Mission B: 582 + 143 Method: Expanded Form
582 = _______________________________________________
+ 143 = _______________________________________________
Final Answer = ________________________________________
Mission C: 627 + 254 Method: Standard Algorithm
627
+ 254
Regrouping Rescue • Standard Algorithm & Independent Goals Page 2 of 2
