Teacher is a career available to Adult Sims in the Sims FreePlay. To access this career, you need to build SimTown Elementary during the Preparing For Preteens quest. The Elementary is located near the Health Hub and in front of SimTown High. You can send your Sims to work there anytime for 7 hours.
There are five levels in the career. Each level has different amounts of Simoleons and XP (Experience Points) each time a Sim levels up.