Addition practice worksheet without regrouping, ideal for elementary math exercises.

I'll solve this addition worksheet for you. The task is to add the numbers in each column without regrouping (carrying).

Let me go through each problem one by one:

First column:
- 348 + 231 = 579
- 797 + 102 = 899
- 649 + 120 = 769
- 630 + 126 = 756
- 144 + 230 = 374

Second column:
- 823 + 352 = 1175
- 153 + 943 = 1096
- 348 + 211 = 559
- 294 + 304 = 598
- 540 + 231 = 771

Third column:
- 438 + 421 = 859
- 728 + 151 = 879
- 271 + 223 = 494
- 336 + 442 = 778
- 516 + 212 = 728

Fourth column:
- 813 + 166 = 979
- 208 + 810 = 1018
- 842 + 125 = 967
- 552 + 342 = 894
- 427 + 242 = 669

Fifth column:
- 500 + 398 = 898
- 137 + 812 = 949
- 110 + 705 = 815
- 295 + 103 = 398
- 329 + 310 = 639

The key point here is that we're adding without regrouping, which means we should only get single digits in each place value (ones, tens, hundreds) when adding. However, looking at the problems, many of them actually do require regrouping (carrying) since the sum of digits in a column exceeds 9.

For example, in 348 + 231:
- Ones: 8 + 1 = 9 (no regrouping needed)
- Tens: 4 + 3 = 7 (no regrouping needed)
- Hundreds: 3 + 2 = 5 (no regrouping needed)
This one doesn't need regrouping.

But in 823 + 352:
- Ones: 3 + 2 = 5 (no regrouping needed)
- Tens: 2 + 5 = 7 (no regrouping needed)
- Hundreds: 8 + 3 = 11 (this requires regrouping - we'd carry 1 to the thousands place)

Actually, I think there might be an error in the worksheet's title "without regrouping" because many of these problems do require regrouping. Perhaps the intention was to practice regular addition, or maybe there's a misunderstanding in the worksheet design.

The solutions to all the problems are as calculated above.