As I recall, the math in the Tech test is related to wattage, amperage, voltage, and resistance. The watt, amp, and volts part is about understanding proportions. Ten amp at 100 volts is equal to 1,000 watts, They may change the voltages or other values, and expect you to solve for 'x'. Simple algebra; no math genius is necessary.
Understanding resistance is the same principle. Look up ohm's law and learn thru online examples. It isn't really that hard - and ther is lots of places online to learn that part. Basic electricl principles are all they are asking. The General exam is a bit more complicated - and the Extra exam requires a working knowlede of various circuits. So - study a bit online and I'm confident you will nail it!