Yea. Just drop maths altogether. That way you can join the innumerate majority and flounder around in life. Plus, there's the benefit that since you would have dropped maths, it's likely your offspring won't be that good at maths since you hate it yourself and dropped it, thus the viscious cycle continues, ad infinitum, ad nauseum.
Sure, maybe I'm bitter. But I still have a point.
Azzie, you're smart, obviously, and enough of an individual to not follow the two sheep above me. I'm quite sure you know that if you put the effort in, you'd get some rather good results out of it. I say that because of two things: one, you're smart, and two, even the worst dullard can do well in maths if they put enough time and effort into it.
Still, there's the question of units. If keeping extension 1 maths would give you an odd amount of units, there really is no point. In terms of time required to verse gains, an odd amount of units is a bad idea. Of course, by the same token if you have an even number of units WITH EM1, then it is probably a better idea to keep it.
A single extra unit won't do squat to save your UAI if you screw up in another subject.