Perhaps make them aware how important it is with examples from nature?
https://duckduckgo.com/?t=lm&q=fibonacci+in+nature+examples&...
But probably zeroth, most important, is modelling good behavior. Kids are mirrors.
My parents would reward me by letting me pick out a book at the book store. I'd be excited the whole week.
I may feel differently about reading it I had been forced to read and rewarded with something else, like junk food.
I appreciate the idea of harnessing rebellion and I'll think more on how to apply that to my parenting :)