When my daughter was in second grade, she reminded me of an important lesson about motivation for learning.
My daughter's teacher wanted to encourage her class to read. To do this, she offered what was, in effect, a bribe.
My daughter brought home a reading log to complete for the week. She was supposed to read for at least 20 minutes each day and then have an adult initial that she had completed the reading for the day. If she returned her completed form at the end of the week, she could choose a sucker from the teacher's "reward stash."
She regularly read on her own, so she was excited to participate to receive what she considered to be a slam-dunk reward. I gladly signed her reading form for her after much more than 20 minutes of reading.