I think you could also have multiple pipe cleaners coming from one number and students have to show multiple ways to add numbers to get to that number. Counting with pipe cleaners and beads. Great for fine motor development too.
DIY Wooden Shape Puzzles - In The Playroom How to make your own DIY Wooden shapes puzzles. These are pretty simple, and so cute and fun! A great way to work on learning shapes with toddlers, and also colours