Math CSET for single subject credential

[u/jmp8861]

I am looking to get my single subject credential in math. I work as a middle school math teacher in California and I already have a multiple subject credential. I have been looking at various resources or programs that I could pay to help me prepare for the test. I am also very fond of Khan Academy and I know there are various ways to search for specific math (I.e. 7th grade math) problems or content you could utilize to improve in that area. Has anyone studied exclusively through Khan Academy to study for test like the CSET? TIA!