The corrected sentence is: "527 + 346 = 873 because 2 + 4 = 6 in the tens place, but carrying 1 from the ones (7 + 6 = 13) makes it 7, not 6." The error was regrouping error: the original sentence "527 + 346 = 863." needed to be fixed.

The corrected sentence is: "682 - 345 = 337 because 8 - 4 = 4 in the tens place, but borrowing 1 for the ones (12 - 5 = 7) makes it 3, not 4." The error was borrowing error: the original sentence "682 - 345 = 347." needed to be fixed.

The corrected sentence is: "438 + 295 = 733 because 8 + 5 = 13, carry 1, then 3 + 9 + 1 = 13, carry 1, then 4 + 2 + 1 = 7." The error was computation error: the original sentence "438 + 295 = 623." needed to be fixed.

Add ones: 1 + 9 = 10, write 0 and carry 1. Add tens: 6 + 2 + 1 = 9. Add hundreds: 3 + 4 = 7. The sum is 790.

Subtract ones: 4 - 8 needs borrowing, so 14 - 8 = 6. Subtract tens: 6 - 3 = 3 (after giving 1 ten away). Subtract hundreds: 5 - 2 = 3. The difference is 336.

Add ones: 5 + 7 = 12, write 2 and carry 1. Add tens: 8 + 4 + 1 = 13, write 3 and carry 1. Add hundreds: 2 + 1 + 1 = 4. The sum is 432.

Since 3 < 6 in the ones place, borrow across the zero: 13 - 6 = 7, 9 - 5 = 4 (tens), and 7 - 4 = 3 (hundreds). The difference is 347.

True. Since 500 has zeros in the ones and tens places, you must borrow from the hundreds to have enough to subtract 263.

True. Add ones: 4 + 6 = 10, carry 1. Add tens: 9 + 0 + 1 = 10, carry 1. Add hundreds: 1 + 3 + 1 = 5. The sum is 500.

False. 750 - 425 = 325, not 335. Subtract ones: 0 - 5 needs borrowing, 10 - 5 = 5. Tens: 4 - 2 = 2. Hundreds: 7 - 4 = 3.