Should I sit through reading and writing and only take math?

I already have a strong score for the school I'm applying to (1430), but I want to improve my math score right now I only have a 700 math which is a bit below the average at the school I'm applying to, except my reading is a 730, above average at the school. So, my idea is to take the December 2nd SAT and just sit through the reading and writing then destroy the math. The idea is that instead of wasting energy on the first two sections I can rest my brain and be fresh for the math and then just superscore my current EVBRW with my new math score. Is this a good strategy? Will schools see that I scored a 200 on the EVBRW? Or when I superscore will they not see it? Does it matter if they do?