Master 3-digit sums with place value and carrying tricks! · For ages 7-11
Hello, learner! Today Pip the Owl and Mia will teach three-digit addition.
We will use hundreds, tens, and ones columns.
You will learn no-carry sums, carry sums, and checking methods.
At the end, you can take a final quiz and earn your certificate.
In 3-digit addition, we still add numbers together, but we use bigger values.
Each number has place value: hundreds, tens, ones.
The answer is called the sum.
Example: 247 means 2 hundreds, 4 tens, and 7 ones.
We add matching columns only: ones with ones, tens with tens, hundreds with hundreds.
Write one number under the other so columns line up.
Ones under ones, tens under tens, hundreds under hundreds.
Example: 324 + 215.
Keep place value straight to avoid mistakes.
Neat columns make big sums easier.
Which columns must be aligned?
Some sums need no carry at all.
Example: 241 + 126.
Ones: 1+6=7, tens: 4+2=6, hundreds: 2+1=3.
Answer: 367.
No carry means each column total is less than 10.
Now try a sum that needs one carry.
Example: 247 + 138.
Ones: 7+8=15, write 5 carry 1.
Tens: 4+3+1=8.
Hundreds: 2+1=3, so answer is 385.
What is 247 + 138?
Some 3-digit sums need carry more than once.
Example: 368 + 457.
Ones: 8+7=15 (carry 1).
Tens: 6+5+1=12 (carry 1).
Hundreds: 3+4+1=8. Final answer: 825.
Compensation helps when a number is close to a round number.
Example: 399 + 246.
Think 400 + 246 = 646.
But we added 1 too much, so subtract 1.
Answer: 645.
Using compensation, 299 + 148 is:
Always check large sums.
Example: 472 + 189 = 661.
Estimate first: 470 + 190 is about 660.
Exact answer 661 is close to 660, so it makes sense.
Estimation helps catch silly mistakes fast.
Which is the best estimate of 523 + 276?
Let's read examples from easy to harder ones.
1) 124 + 235 = 359
2) 247 + 138 = 385
3) 365 + 247 = 612
4) 489 + 156 = 645
5) 572 + 239 = 811
6) 698 + 175 = 873
Tap each card and read the tip. Then solve one 3-digit sum using that idea.
Use this quick memory clue:
🌟 “Hundreds, Tens, Ones — line up and solve!” 🌟
Tap each row to reveal the meaning.
Now let's level up to 3-digit addition.
Always add by columns: ones, then tens, then hundreds.
Example 1: 247 + 138
Ones: 7 + 8 = 15, write 5 carry 1.
Tens: 4 + 3 + 1 = 8. Hundreds: 2 + 1 = 3. Answer: 385.
Example 2: 365 + 247 = 612.
What is 236 + 157?
Answer 6 three-digit addition questions. You need at least 5 correct to earn your certificate! ➕
Type the name above, then click Download or Print!