I use a pattern train during calendar time as a quick, fun and easy way to teach and review patterns.
I made a simple pattern holder (see below) out of a piece of folded and taped poster paper (that light weight cardboard).
I tack it to my calendar board and fill it with the pattern trains.
Each day I pull out one train, bit by bit, as we talk about and predict what the pattern might be.
Click on the image above for your copy of the trains (you'll need to colour them in).