Step 2: Prep the tubing
Most pipe insulator has one side pre-cut almost all the way through. Use your hands to completely split the pipe open.
Next, use a pair of scissors to carefully cut the tube in half. After cutting a few inches, you can simply hold the scissors open and slowly pull the tube through the open blade. I find that this technique is faster and cuts straighter than making repeated cuts.
You'll need about 4 half-tubes per student.