I personally feel that blocks are one very excellent tool of learning for kiddos. When i was young, my mom will just use a set of poker cards to play with me many interesting games and it can keep me entertained for hours.. we played mainly memory games and that might explained why i had strong memory and is able to study very easily.
KD particularly like blocks too. Just that probably he is only 3yo now, it can only keep him entertained for around 10 to 15 minutes. He is the one that initiates pulling the box of blocks out from his learning box.
With the blocks, we can:
1) Build them into tall towers, a long choo choo train, as well as build many different shapes quickly
2) Count them
3) Separate them one by one to this is for mommy, and this is for KD
4) Identify the shape and color printed on the blocks
5) Sort them accordingly to different shapes or different colors
6) Show him a combination of blocks and ask him to recreate exactly the same
The possibilities are endless, it all depends on the creativity of the mom and child at point in time while playing! :)