A great way to show place value and expanded notation with graph paper! You could add place value names (ones, tens, hundreds, etc.) instead of the title "How to Expand Numbers" to demonstrate both concepts.
Another pinner: Measurement -- Longer/Shorter. Easy for my five year old but good practice for her to work independently. Was surprised my two year old sorted and match the lines on her own the way they are in the picture. Super easy to put together.