How did Atticus get Jem to accompany Scout?

It seems that Atticus bribed Jem to accompany his sister to her first day of school. 

Jem condescended to take me to school the first day, a job usually done by one’s parents, but Atticus had said Jem would be delighted to show me where my room was. I think some money changed hands in this transaction, for as we trotted around the corner past the Radley Place I heard an unfamiliar jingle in Jem’s pockets.