用积除乘数得被乘数或用积除被乘数的乘数624（被乘数）×78（乘数）=48672（积）48672÷78=624或48672÷624=78
624x78验算？先算出1结果后再验算：624x78=48672验算：48672/78=624或者是：48672/624=78
