One of our centers this week asked the children to look closely at the attributes of our rock collection. “Which ones will roll?” was posed as the main problem. However, this wasn’t quite so simple as it seemed. First, they had to decide what might cause a rock to roll. Second, the shape of the rock needed to be considered.
Some children suggested that wind was important to rolling. A few experiments later, they found that although we can occasionally blow on a tiny rock hard enough to move it, it generally doesn’t roll by air power alone.
A few suggested that shaking and throwing a rock would cause it to roll. (I think this came from our use of dice last week.) After a quick discussion about the safety of this experiment, it was unanimously decided that though this option might work, it was too dangerous to try in our classroom.
Eventually, the inclusion of hills was suggested by one child. Ramps and slopes galore appeared in the block area. Above you can see Mrs. Pless helping a small group observe and analyze a single rock as it goes down the incline. Did it roll or just slide? If it didn’t roll, why not? We haven’t completely solved this riddle yet, but we’re well on our way. We’ve certainly seen this replicated outside with balls on the hill. It’s interesting that the students have not made the connection between the rolling balls and the mostly sliding rocks. Roundness is an attribute that we’ve not quite pegged, yet.
While keeping track of which rocks rolled, they children also practiced their use of tallies to keep a record. As you can see, we use basic, one-to-one tally systems in Pre-K. At this point, we are most interested in seeing that each roll is recorded with only one line. We also practice re-counting our recordings by assigning only one number to each line as we count.