Absolutely! Students need to recognize what's right and what's wrong. If they are sheltered from seeing what's wrong how will they ever recognize what's right (and vice versa?)
The approach you suggest is called 'whole math'. The theory is if you let kids 'discover' the truths of mathematics for themselves, they will understand math better, and ultimately learn it more soundly.
In practice it's been an unmitigated disaster. Where it's been adopted, math scores have plummeted. Our experience with it, in fact, has been similar to that of 'whole reading'.
Interestingly, both are considered to be left-wing educational ideas.
And now the IDers want to implement "whole science". Sure, our students' science performance will plummet relative to the rest of the world. But if we just add some more self-esteem programs, they'll feel really good about themselves.