Your choice of adjectives is excellent. You're lucky you inherit your math genes from my side of the family. Since everyone turned in a book report we will have an extra recess today. Whether such rewards motivate more learning, discourage learning, or have no effect at all is a subject of debate. Research reviewed by the Northwest Regional Educational Laboratory gives parents and teachers guidance on this subject.
Praise is the most commonly used reward or reinforcer in the classroom.
It turns out that not all praise is created equal. In the language of praise a whisper speaks louder than a shout. You are one of the few who understands what research is all about. Effective praise is specific and informative. Teachers who are careful with giving praise are more effective than those who gush over a correct answer.