For this activity, you will need a number of small containers, depending on the sorting criteria you chose, and an assortment of buttons (i.e. size, color, number of holes on the button).
Place the buttons on a plate or in a larger container. place the small containers in front of the child as well. Allow the child to sort the buttons by size, color, number of holes, etc.
As the child picks up each button, encourage him to use his thumb and pointer fingers to help with developing pincer grasp.
To work on thumb opposition, ask the child to pick up each button with his thumb and middle finger, thumb and ring finger or thumb, and pinkie.