Did he show any work or just give the answer? Technically, unless clearer explanations are given, both methods should be totally acceptable and I don't know why the teacher would have a problem with either. As a math teacher, I just like the kids to find one method and stick with it. I don't care which it is but since it is a very important concept that will be used a lot, they need to learn one and remember it.
It is disappointing if the teacher is marking it wrong just because she doesn't like your son. That 'susually hard to do when you are a math teacher!!! I've come across some teachers who will give the benefit of the doubt and award many part marks to a student they feel knows what they are doing but award few part marks to students who don't usually get it. Usually the student can go to the teacher and argue for those marks.
If this was a new teacher for him he could try to build a relationship but at this point, I'm not sure what to suggest other than going in for extra help and trying to convince the teacher that he really wants to do well.
Well, he's a 2nd year student for her and their troubles started last year... He's had several quizzes and tests he's brought back for review, but this is the first one this year. DS just believes she doesn't like anyone who doesn't get straight A's (it's an honors program) She doesn't connect with DS at all, we've hired another math teacher as his tutor twice a week. He wishes the tutor could be the class teacher because they totally get one another. Since he started with the tutor he's getting A's, but his regular teacher knows DS is working with the other teacher. The work he's doing with the tutor is totally coming through for him, and he's where he now needs to be, and he is HAPPY! We brought the problem to the tutor before I posted it, and he says it is correct for what was asked. The quiz doesn't ask for you to show your formula, so DS showed NO formula's for any problem. However, I suspect she marked him down on this problem for lack of doing so. The teacher we are working with thinks this isn't right, but there's really no way for us to fight for the points. DS is going to take the tact mentioned above, saying he worked on it over the weekend and could she please explain the answer to him.... then we'll see if she will mark the problem correct or not, or explain why she marked it wrong.
It's amazing what the tutor (who teaches other honor programs at the high school) can do with DS in one session, covering a week's worth of what is done in class. The other session of the week is dedicated to the work he did in this woman's class last year where he is not showing a strong enough foundation.
We're trying to teach DS that you will not always get the teachers you like, or the teachers you need, if it's truly a problem, then find a tutor who can help you through whatever troubles you are having and that you can relate with. We are extraordinarily lucky to have the resource. DS says at least 3/4's of the class has a much lower grade than he does, but unfortunately they are all supposed to carry a 92 to stay in the class. DS is 4 points short, but based on his trajectory since hiring the tutor we will fight for him to stay in the class.
It's complicated... I hope for a teacher DS connects to next year, meanwhile, if he is dropped from the class, he breezed through the college entrance exam to take the College Algebra class & we'll have him take it in January (he's in 8th grade). I found a really good professor, and DS has really good academic references so they'll let him take it at the college.
In my sons exact quote "He (the tutor) owns her (the teacher)", he's totally psyched to be working with the tutor... he really likes math, but he really doesn't get this teacher.....
If I were his teacher I would accept both and maybe note why I would probably prefer the second formula.
