Recently Elliott had started doing a lot of "weighing" by holding his arms out, and asking me which hand is holding the heavier or lighter object. It just so happens that a few weeks ago I placed an order that included many math manipulatives. Elliott is a very hands-on learner, so I allocated a good chunk of our Kindergarten budget to math resources (my weakest subject) and many fun, hands-on materials.
One of the items was a balance scale. Even though we're not "officially" schooling yet, I figured now was as good a time as ever to introduce it, so that when it comes time to use it for more math activities he will already know how it works.
We started out using the linking cubes that I had also purchased, and he quickly realized how to compare amounts. Although you can't see it in the pictures, the front side has a storage drawer with an arrow, and I showed him how to make sure it was balanced by comparing the line on the balance to the arrow below.
It wasn't long at all before he was ready to move on to comparing other items. This was part of a mast from his pirate ship.
He also did several experiments with dinosaurs that he swiped from our homemade dinosaur table.
This activity was perfect for practicing math vocabulary...heavier, lighter, more, less, equal...so we were able to do some inadvertent learning during our play!