Darko found the sum of 324 and 57 to be 894. What error did he make?

Question

(1 point)
• Darko did not regroup correctly after adding the ones digits.
• Darko did not align the digits by their place value when he set up the problem.
• Darko added 324 and 75 by mistake.
• Darko multiplied the numbers instead of adding them.

Answer 1

To determine the error Darko made, let's first correctly add 324 and 57.

1. Align the numbers:

  324
+  57

2. Add the ones digits:

   • 4 (from 324) + 7 (from 57) = 11. Write down 1 and carry over 1.

3. Add the tens digits:

   • 2 (from 324) + 5 (from 57) + 1 (carry) = 8.

4. Add the hundreds digit:

   • 3 (from 324) + 0 = 3.

So, combining these results, we have:

  324
+  57
------
  381

The correct sum of 324 and 57 is 381. Darko found it to be 894, which suggests a significant error.

From the options provided:

• Darko did not regroup correctly after adding the ones digits. - This could be true, but it alone doesn't explain the discrepancy.
• Darko did not align the digits by their place value when he set up the problem. - If he didn't align the digits, it's possible he added incorrectly.
• Darko added 324 and 75 by mistake. - This would result in 399 (not 894).
• Darko multiplied the numbers instead of adding them. - 324 multiplied by 57 is also not 894.

The most likely explanation is that Darko did not align the digits by their place value when he set up the problem.

So the best answer is:

• Darko did not align the digits by their place value when he set up the problem.