New Materials: Cylinder Knobs

We picked these cylinder knobs up yesterday, along with a lot of other wonderful manipulatives from a local Montessori school clearing out overstocked items. Sophia and Austin tested them out, and immediately got the concept with very little modeling. I expected to have to demonstrate how to hold the cylinder by the knob, using the thumb and two fingers, and not touch the actual cylinder, so they could visually discriminate the size, but alas, they took turns figuring it out with very little help. I even added the 2nd set of (deep) cylinder knobs out, mixed them up with the shallow knobs, and after a few minutes, they were all returned to their correct sockets.