Final answer:
The question seeks to identify Chen's error in a division problem, but without the specific problem, we can only hypothesize about common division errors such as incorrect steps, decimal point placement, or miscalculation of remainders or quotients.
Step-by-step explanation:
The question appears to relate to a division problem that was completed by a student named Chin. However, there seems to be a typo in the question, as 'Chen’s air' does not provide clear context. Assuming the question meant to ask what Chen's error was in the division problem, we would need to see the problem itself to identify and explain the mistake.
Without the specific division problem, one can only provide general guidance on common errors in division such as incorrect division steps, misunderstanding the placement of the decimal point when dividing decimals, or miscalculation of remainders or quotients. To help Chin understand what went wrong, he should review the division steps one by one and compare his results to a correct calculation. Depending on Chin's problem, the error could lie at any point in the division process.