It is not uncommon, that some teachers or schools introduce pseudo-science, like creationism, as a part of curriculum.
Given that it is hard to change school quickly, how to deal with such situation?
Everything ofcourse depends on the sort of pseudo-science and the amount of it your child is exposed to. If it is something that bothers you and keeps coming back. I would definitely talk about this with the teacher, the principal, etc. But when it's really part of the curriculum, it gets political fast and there probably isn't a lot you can change about it in the short run.
But regardless if you are able to change something about it: Talk to your child about it. Make this a learning experience for him/her to develop their own critical thinking skills. What does your child think himself? Does he/she believe the teacher? What would be a way to prove the teacher is right? What would prove him wrong? When should he believe an authority figure, when not?
Also it's good to consider that your own influence as a parent, on norms, values and ways of thinking, is far greater than the influence of a single teacher, or even a school.
Probably the best guides to this topic come from the National Center for Science Education.
In brief, the best approach seems to be to first contact the teacher (in writing) and ask about any materials presented in class that had to do with the pseudoscience. Do not engage them in any kind of debate, just ask (nicely) what they presented and whether you can see the materials. After that, depending on their response, contact (in writing) their supervisor with your concerns.
Dale McGowan, who edited Parenting Beyond Belief, has a series of blog posts about this exact topic, starting here.
You can write a letter to an administrator asking to remove your child from a particular unit of study and see if that can happen if you feel just begin open and having open conversations with your child about it isn't enough.
However, I would be extremely cautious before taking such an extreme route because such a choice will:
I would personally go with philosodad and Tim h. but thought this option should be included because it does exist in most public schools at least and offers the school feedback as to how strongly you feel if you choose to use this option. It is a middle of the road option to pulling your child out of the school and switching schools because of it.
There's nothing wrong with teaching children Truth. If the teacher proposes creation science with a basis of fact, then it's not going to harm your child. Same goes for evolution.
The problem comes in when the teacher begins to tell their students blatant lies about one topic or another. There are plenty of evolution lies taught in the textbooks, you should be more concerned about these.
There are numerous very accomplished scientists that have gone from evolutionists to creationists based on the evidence that they've found. If that's the way that the evidence points, why would you fight it?