Back in 1990, my husband started a pest control company, and I was his head bookkeeper/finance officer. Even tho I only had to go to the office twice a week, I always took my then 2 year old son with me, up till he went to school. He always occupied himself playing quietly with toys. As he grew older, especially in the summers when school was out, he came with me until I felt he was old enough to stay by himself, around 14 or so, for a couple of hours. But by then he wanted to earn some money, so he went on small jobs with hubby, and learned some of the ropes, through age 20 or so. Even after hubby sold the company in 2007, my son worked two summers for the new company. Now he's married, with a beautiful wife and baby girl, just turned 29, has a good job in the banking industry, and lives 2 hours away. So, I believe the time he spent with our business helped him develop healthy work habits. So as long as the children are quietly playing, doing school work, or even helping out in the business, I see no problem with it.