Detailed Explanation of Adding Three-Digit Numbers with Regrouping 🧮

When we add three-digit numbers, it is very important to remember place value. The place value tells us what each digit means: the digits on the right are the ones, the middle digits are the tens, and the left digits are the hundreds.

Why Place Value is Important 🔢

Each place value is worth ten times more than the one to the right. So, the ones are single units, the tens mean groups of ten, and the hundreds mean groups of one hundred. When adding, we must add the digits in the same place value first.

What is Regrouping (Carrying Over)? 🔄

Sometimes, when you add the digits in the ones or tens place, the total is 10 or more. Then you have to regroup or carry over some of that number to the next place value.

For example, if you add 8 + 7, you get 15. You put the 5 in the ones place and carry the 1 over to the tens place.

Step-by-Step Example to Add 245 + 378 📝

  1. Add the ones: 5 + 8 = 13
    • Put 3 in the ones column.
    • Carry over 1 to the tens column.
  2. Add the tens: 4 + 7 = 11, plus the 1 you carried over makes 12
    • Put 2 in the tens column.
    • Carry over 1 to the hundreds column.
  3. Add the hundreds: 2 + 3 = 5, plus the 1 you carried over makes 6
    • Put 6 in the hundreds column.

So, 245 + 378 = 623.

Remember ✅

  • Always start adding from the ones place.
  • Carry over if the sum is 10 or more.
  • Add the carried over number to the next place value.
  • Write the answer carefully by place value.

Using this method helps you add any three-digit numbers correctly! Keep practising, and you’ll get really good at adding with regrouping.

20 Examination-Style Questions on Adding Three-Digit Numbers with Regrouping – With Answers 📋

Here are 20 examination-style questions on adding three-digit numbers with regrouping, perfect for Year 3 students. These questions will help you practise adding numbers carefully and show how to carry over numbers when needed.

Questions ❓

  1. 236 + 487 = ___
  2. 142 + 379 = ___
  3. 509 + 276 = ___
  4. 398 + 415 = ___
  5. 624 + 187 = ___
  6. 781 + 229 = ___
  7. 354 + 468 = ___
  8. 295 + 376 = ___
  9. 413 + 589 = ___
  10. 827 + 135 = ___
  11. 663 + 238 = ___
  12. 754 + 289 = ___
  13. 342 + 758 = ___
  14. 198 + 637 = ___
  15. 529 + 371 = ___
  16. 484 + 359 = ___
  17. 615 + 587 = ___
  18. 299 + 462 = ___
  19. 731 + 269 = ___
  20. 844 + 126 = ___

Answers ✔️

  1. 236 + 487 = 723
  2. 142 + 379 = 521
  3. 509 + 276 = 785
  4. 398 + 415 = 813
  5. 624 + 187 = 811
  6. 781 + 229 = 1,010
  7. 354 + 468 = 822
  8. 295 + 376 = 671
  9. 413 + 589 = 1,002
  10. 827 + 135 = 962
  11. 663 + 238 = 901
  12. 754 + 289 = 1,043
  13. 342 + 758 = 1,100
  14. 198 + 637 = 835
  15. 529 + 371 = 900
  16. 484 + 359 = 843
  17. 615 + 587 = 1,202
  18. 299 + 462 = 761
  19. 731 + 269 = 1,000
  20. 844 + 126 = 970

How to Check Your Work 🔍

  • Add the ones column first. If it is more than 9, carry over to the tens column.
  • Add the tens column next, including any number you carried over.
  • Finally, add the hundreds column, including any carryover from the tens.
  • Write the total answer clearly.

Keep practising these adding three-digit numbers with regrouping questions to get better at addition and handling carrying numbers!