Mikage, as a current math (and soon physics major by double major), you do not need to take Chemistry, you can opt it out with Physics instead.
Here's the required courses to graduate as a math major:
http://www.editor.uci.edu/07-08/ps/ps.5.htm
Just a bit of warning, if you're not prepared in basic Java programming, that ICS 21 or related programming course WILL kick you in the balls. So many non-ICS majors who never did programming will be immediately held up during their first lab, while ICS majors who never did programming will have their dreams (mostly game design >_>) ruined and dashed away as it happened to my roommate.
Even though I had 3 years of programming experience, I still thought the mid-term and final for ICS 21 was difficult (but still got an A ^_^)