Scrape what you can away from the floor with your fingernail. You can use a razor blade or utility knife if you want to, however you do increase the risk of scratching the floor.
Apply a citrus cleaner or rubbing alcohol onto the rubber glue spot and allow it to sit for a few minutes.
Blot at the glue spot with a clean rag, then rinse the area with warm water and dry it off thoroughly.
Add some hydrogen peroxide onto the rubber glue spot if it still hasn't removed all the way yet. Allow the peroxide spot to sit for up to 30 minutes, keeping it covered with a towel or rag to block the light.
Wash the floor over with more warm water and dry the area again. The rubber glue spot is now completely gone.