My daughter isn't at that age yet, but I imagine that helping to lead the conversation/exploration with the right questions (rather than providing complete answers) might be a sound approach?
A funny anecdote - I taught my daughter the principles (not the mechanics) of trigonometry and the unit circle when she was in 6th grade. Simply because she asked. When she was taking trig in 10th grade, she said "remember when you told me about ...".