@pidachhajindaki, one needs your transkript to see to provide precise answer to your question. Provided two assumptions hold correct, first you completed 120 credit hours, second you want to bump up 2.3 to 3 over all, then it is monumental task as you need to take at least 27 (3 credit) classes with perfect A in each class.
If you are seeking admission to MS in math, many universities may consider your undergrad math courses only and do not give shits to shitty liberal humanities courses. If you need 3 gpa on only a particular area, you may need to take significantly less number of classes, which cannot be answered for sure without looking at your transkript.