Building with manipulative toys is something that is a building block-type activity. The strength and dexterity developed helps with other things, such as snapping, zipping and writing.
When I brought Axel home it was clear he'd never seen legos or duplos before. I put them in front of him to see what he would do. He would pick them up one by one and examine them, then set it aside before taking the next one out of the bucket. Once they were all out, he looked at me like, "Now what?"
Once I showed him how they go together, it only took him a day or so to discover he loves duplos! They're one of the first toys he chooses when it's play time. The first day he just built tower after tower. Then he discovered the top of the bucket can be used too, and that you can put all kinds of pieces together.
He works SO hard on the blocks.
And then...what's this? The big truck can be played with at the same time?
Look out Mom, you're in my way!