This is a fun activity to explore the science of balance and weight in the classroom. Have the students use the classroom balance scales to see how much items from their pencil boxes weigh. Does it weigh 1 bear, 2 bears, 3 bears, or more?
Have set up befor going on a nature walk! - I love math that is so visual. This link will open to an article on Kindergarten Math but so many of the activities can be adapted to younger students, like the leaf activity pictured here.