Playing with cups

At the age of 10 months babies start to understand the concept of "larger" and "smaller".
If you see your baby making experiments with things, putting one into another, that's it!
Give your little one two plastic cups of varying size, let the little one play with them.
The next day offer him/her three cups, then - four cups, etc.
Make photos of the process, upload to the App. Write about your baby's new skills.