Your child is beginning to use logical reasoning to solve day to day problems. Besides finishing puzzles with eight or less pieces, sorting shapes, following patterns with stringing beads, he will also be able to stack rings or other objects with holes.
What you need to know
At this stage, your child can stack rings on a peg in order of size and colour. Stacking objects like blocks or rings in the form of a sequence or pattern boosts early mathematic skills in your child. Give him time to explore different objects and allow him to figure out solutions. If you find him unable to solve something, offer guidance. As your child stacks the rings, talk about size, colour and work on building his vocabulary. For instance, big, bigger, small, smaller etc. As he accomplishes his task, offer ample praise. This builds his self-esteem.