MathIsimple

Multi-Digit Operations

Master adding and subtracting three-digit numbers with regrouping!

3rd Grade
Operations
~35 min
🎮 Interactive Activity: Multi-Digit Addition

Add three-digit numbers step by step!

Carry
Hundreds
Tens
Ones
2
4
7
+
1
8
5
?
?
?
1. Multi-Digit Addition

📊 Line Up Place Values!

When adding multi-digit numbers, always line up ones under ones, tens under tens, and hundreds under hundreds. This is called "aligning place values" and it's crucial for getting the right answer!

247
+ 185
432

💡 Remember: Always start from the right (ones place) and work your way left!

📝 Example: Addition with Regrouping

Problem: 358 + 276 = ?

Step 1: Ones: 8 + 6 = 14 → Write 4, carry 1

Step 2: Tens: 5 + 7 + 1 = 13 → Write 3, carry 1

Step 3: Hundreds: 3 + 2 + 1 = 6

Answer: 634

🎯 Why regroup? When a place value sum is 10 or more, we "carry" the extra to the next place. This is regrouping!

🔢 Practice Tip

Try adding 234 + 567 step by step. Check: ones (4+7=11, write 1, carry 1), tens (3+6+1=10, write 0, carry 1), hundreds (2+5+1=8). Answer: 801!

2. Multi-Digit Subtraction
3. Understanding Regrouping
4. Estimation Strategies
5. Checking Your Work

Practice Time!

Practice Quiz
10
Questions
0
Correct
0%
Score
1
What is 245 + 138?
2
What is 567 - 234?
3
What is 489 + 276?
4
What is 800 - 356?
5
Estimate 487 + 312 to the nearest hundred.
6
What is 156 + 289 + 45?
7
What is 703 - 468?
8
Which is the best estimate for 592 + 411?
9
What is 1000 - 573?
10
Sam had 458 stickers. He got 167 more. How many total?