After watching the children have so much fun with the colored tiles that came as part of our RightStart Math kit, I decided that they needed more shapes to play with. I found this set of pattern blocks on Amazon for about $5-10 less than all the other sets. It shipped quickly and the quality is great. I don't know why it costs so much less, but I'll take it.
Then I found an amazing set of printable patterns at Prekinders. She has the patterns in color version and in black in white. I printed them in black in white. It is a bit more challenging for the children and saves color ink.
When we first started the children were really frustrated because their pattern blocks kept sliding around. I cut some large pieces of contact paper from a roll I got a while back and taped them sticky side up in front of each child. This allowed me to slide the patterns under the contact paper. They could build their designs and then slide the pattern out from underneath to see the pattern. You can also just slide blank paper under the contact paper and let them make up designs of their own. I played too. We all had great fun and our kitchen table has been taken over for two days now.