Final answer:
The student most likely made an error in the unit conversion from tons to pounds. They may have made a mistake when multiplying 20 tons by 2,000.
Step-by-step explanation:
The student most likely made an error in the unit conversion from tons to pounds. To convert tons to pounds, we need to multiply by 2,000. In the given table, the student crossed out 40,000, which should have been the result of converting 20 tons to pounds.
The correct answer would be 40,000 pounds. Therefore, the student likely made a mistake when multiplying 20 tons by 2,000, resulting in an incorrect entry.