The problem with simply teaching a science curriculum to a child, is that by definition, it is doing the opposite of what science is all about.
Schooling systems differ on how science is handled in the classroom. However, the general trend is of spoon-fed learning.
Rather than teaching your child "science", take a more relaxed stance and simply teach your child to think for him or herself. Reasoning and logic etc. Question their assertions and assumptions with what you know, and don't always assume what you know is right.
You could both go searching for a better (not correct) answer to a problem.
Science is about searching for these "better" answers. And in turn, being humbled by more complex and fuller answers in the future.