Stacking is more than playing
When children sit and stack they are doing more than just playing. They are exploring and solving. For toddlers stacking toys you introduce ought to be simple with clear goals and not over whelming or burdening. Introducing one ring and gradually increasing the number of rings in recommended.
Hand-eye coordination, fine motor skills and problem solving
Your little one will be incorporating numerous skills into a simple activity like stacking. They get to stabilize and explore all the skills like Hand-eye coordination, fine motor skills and problem solving. It also exercises their grasp and release movements.
Understanding spatial relations and Numbers
While exploring a stacking toy a child gets an idea as to how spaces work and what can fit into what. It makes them aware of space and size. The foundation to numbers can be laid with the stacking toy. We can encourage them to count and sequence objects.
The number of language explosions is myriad. Your toddler can learn numerous new words like "big", "bigger", "small", "smaller" and prepositions like "on top of", "over", "under" etc. This can also be used to introduce colors.
The room for creative play is very important for a complete development. Creative play will begin after the child has achieved the primary goal of the toy. This allows cognitive development in your little one.