I ABSOLUTELY LOVE this super simple Missing Numbers Activity. You only need Number Magnets, Dry Erase Marker, and a Dry Erase Board. The best thing about this activity is that it takes less than 3 minutes to set up and its super effective.
When I have 5 - 10 minutes to spare, I always do this quick activity with my daughter. Plus you can also do this with Alphabet Magnets. The opportunities are endless with this!!!