Start with one "magic" bean taped to the bottom along with an invitation to draw what it would become. Lovely! Reading Jack in the Beanstalk together would be a nice rainy day addition to this project.
Class Messages. This one is for Measurement. You could write messages and sign them from different characters/animals to fit your weekly theme/story...Brown Bear, Pete the Cat, Little Quack, Goldilocks, etc.
I like this hands-on approach to maths; great for those outdoor learners ~ this link opens up to an article on Kindergarten Math but so many of the activities can be adapted to younger children, like the leaf activity pictured here.