I gave J a bowl of colored stones (for his two different colors, but as he gets older I can add more colors) and an empty ice cube tray. The first step was to fill each section with one stone (I wasn’t concerned with colors at this point). It’s basically a simple pattern, each spot needs one stone. Then he emptied the tray and I had him fill one side with red stones and the other side with blue stones.
I’ve done the same thing with the colored pom pom balls. Really you could use anything small enough to fit. Somtimes changing the sorting item is enough to make get J interested again, especially if it’s not really a toy! Oooh, I get to play with rocks now! Oooh paperclips!!! Ooooh erasers!!!
Age? First done (with pompom balls) around 16 months; color sorting at 19 months
Try Again? Yes, as long as the difficulty increases with age. As he gets older and better at counting I can specify the number of stones in each section or have him add one more stone in each subsequent section (so he has one stone in box one, two stones in box two, …). I can also incorporate motor skills by having him use a spoon or tongs to transfer the stones.