Here is another Montessori visual sensory activity.
The goal here is for the child to arrange the rods from the shortest to longest. In this activity, the child visually learns what 'short/shorter/shortest' and 'long/longer/longest' means.
Lay the rods in random order.
Have the child arrange the rods according to it's length.
Read here to learn more about this activity.
Again, you don't need to own these Montessori materials to conduct this activity. Think out of the box and look around your house to see if you can improvise. You can, say, use straws and cut them accordingly?