I had the older boy pour the powder into a medium sized plastic mixing bowl. He said that this wouldn't be enough for him to play with, and he was amazed at how much "snow" the powder turned into when he started to slowly pour water into the bowl.
Once we "made" the snow, I split it up between the two boys and just let them play. The younger boy just liked to touch it. It has a cold wet feeling to it that he loved. The older boy got more imaginative and started making things out of his snow. He first started with a snowball, and then decided he wanted to make a snowman. I was really impressed at how well we were able to make things with the snow.
*If you do get this for your children to play with, I highly recommend taping a plastic table cloth on the table that you can throw away when you are done. I had a really hard time cleaning up when we were done because the snow clung to the table.