In our classroom, we use the three part lesson when a new activity is being introduced. The first part of the lesson consists of showing the child what something is. For example, using this activity tray I would say "This is the sphere," while holding the sphere. I would then pass the child the object and say "Can you say sphere?" The child would say "Sphere," and then pass the object back to me. Then we would do the same things with the cone and the cube. The second part of the lesson is to ask the child to point to each of the objects as you name them. For example, "Can you point to the cone?" After the child has pointed to each of the objects I have named, I proceed to the third part of the lesson, which is asking the child to name each object as I point to it saying "Can you tell me the name of this object?"
When all three parts have been completed the activity can be returned to the shelf. The next day I may bring the tray out again but start the lesson with part two as the child will probably recognize the names of the objects from the previous day's lesson. A few days after that I may begin the lesson at step three. When it is clear that the child knows the lesson well then I will remove the activity and later incorporate the items into a new activity. In this example, the next activity could be learning the difference between a circle and a sphere or later learning about the area and dimensions of the objects.
For some activities the three part lesson may not be appropriate but instead a clear step by step demonstration is needed. When demonstrating, I am careful to do the activity slowly and to use care when carrying activity trays from the shelves to the table by using both hands. Often, the children may not complete the activity exactly as I demonstrated but instead make their own modifications. This is fine as they are probably changing the activity to more accurately suit their learning needs at that moment.