First, introduce the idea of opposites with pairs of real objects from around the classroom, such as an open box and a closed box. Later, present a few pairs of opposite cards at a time and talk about them with your children.
Introduce any new vocabulary, such as thick/thin or full/empty before moving on to other activities.
The 40 cards (6" x 5½") are packaged in a reusable, hinged plastic box. Activity guide included. Ages 3 and up.