Just to level-set parents’ and students’ expectations - B’s and C’s first term in classes that are the kid’s strength are pretty normal as well. Remember this is no longer middle school and parents and kids chose a boarding school, in part, for the academic challenge. At a typical boarding school, 95% of the students will graduate with less than a 4.0 GPA and, (shocking, I know) a full 50% of the class will be in the bottom half of the class. The good news is that they generally do well in both college admissions and in life. 
As the mom of 2 exceptionally lopsided kids, both with mild LDs (math based), I agree that you should definitely let your son pursue his strengths and not lower his math class. Ask about tutors for the weaker subjects - most schools have both student tutors available in the evening and sometimes teachers in addition to the classroom teacher who are available for extra support. My daughter used a tutor for her first semester in her weak subject, and after that she was able to manage on her own (but she was very proactive about seeking out extra help from teachers.) Even if your son doesn’t have a recognized learning difference, if you ask the school, they may also give him extra time to complete tests and other accommodations that will make it easier for him to keep up.
I got 50%/50% “Balanced”
Fun- 80% left for me- my kids struggle with learning languages as well. My oldest went to engineering college partly to never have to take another language course!
Left brain 63% (analytic)
79% left
56% Left. A bit surprised that I’m so balanced. :))
Interesting, I’m much more left-brained than I thought. I guess I always associated left-brain with just being good at math, and hadn’t focused on the fact that it’s really more about being analytical.
Thank heavens I took that test. I’m an analyst by trade. Would hate to think I wasn’t suited for it. 
53/47. I am a bit surprised. No one in my family would accuse me of having any creativity. LOL My kid has even warned me that I would get a reputation as a “rule follower”. The horror. 
63 left brained digital.
The 37 right brained side is creative.
@ChoatieMom. That’s great news about Choate. It is so critical that today’s kids learn to fail and to take risks, but so few do for fear of not getting into college, a job, etc. I read a very good book about this issue, Excellent Sheep by William Deresiewicz and also a great book by Paul Tough, How Children Succeed. (I can also say that at my job, we only hire the top kids (top 1%) from Ivies, MIT and Stanford. These kids resumes are beyond impressive with nearly perfect GPAs and every conceivable award. What has struck me over the years, is that while these are bright kids, whenever things go wrong (or not as planned) or a client offers constructive feedback on their work, these kids really struggle with dealing with those circumstances. It’s as if they have been programmed to succeed a certain way and expect the workplace to reward them with “As”. To me, there are schools skills and real world skills and I wish more schools would focus on building the skills you actually need to succeed in the workplace. It will take an overall attitude change by all constituencies, but I hope we will get there. Even at my job, there is some movement toward hiring a bit more broadly and looking at traits of resilience, grit, etc. (Thankfully). How will kids learn these skills if they never fail at anything?
Wow! 76/24 (order) - now I know why I was a CPA pre-kids!
Edited to add “order”
Left brain Order 80/20
@31cruzan When asked in an interview how she has dealt with failure, my kid was very honest, saying she really hasn’t had an opportunity to experience failure. Seriously, an occasional bad grade on a test here or there doesn’t constitute a failure. A middle-class kid who has had the luxury to be in a private school all her life and do everything she cares to do - she almost feels resentful for being deprived of life struggle! I’m not sure that was the right answer, but at least it was an honest answer.
I always get right-brained on these quizzes (74% this time, sometimes higher). But I spent most of my life thinking I was the left-brained type.
@GoatMama - we felt the same way when filling out Naviance form for college counselor. DS really has had no significant struggles in life, or obstacles to overcome.
@MA2012 I feel the same. During BS application and now college app for my DS at home, there haven’t been any challenges academically nor personally.
@twinsmama, I know people like you: Their creative, imaginative brains always convincing them that they are so rational and analytical!