根据积的小数数位是因数中的小数数位之可得: 如0.25×0.004=0.001中,0.25是两位小数,0.004是三位小数,积的小数位数是:3位, 所以两位小数和三位小数相乘,积一定是五位小数,不正确. 故答案为:错误.