I like using it with children because it tells me so much about what they know. This is usually easy because they ask me if they can continue to higher numbers. The interesting question a group of sixth graders came up with was Does it also work with 5s or 6s or six 4s etc. We shared along the way and came away with a strong sense of order of operations. I do warn you that this is an activity that some find hard in groups, so I am anxious to hear from you.
Kids also have trouble developing a strategy.
They tend to be very linear. First the one, then the two, etc.