"I Wonder" boards are a teaching strategy that can be used in the classroom, as well as during science learning opportunities in nonformal settings, such as after-school science programs or summer camps.This simple strategy has led to deeper science exploration in 4-H, as young people learn alongside program staff, teachers, or volunteers. (The term non-formal is used to designate learning experiences that are designed and structured to engage learners outside of the formal school day and led by trained staff or volunteers.) It has been used with youth in grades K-8. This article highlights the use of "I Wonder" boards in scientific investigation as used in non-formal learning settings by sharing two examples: a summer-long monarch larvae monitoring class and a workshop on polymers.