Maths Betrayal

I thought English pissed me off. Maths is pissing me off even more right now. The two-unit maths assessment worth 20% is set to be this Friday. I thought I was okay. But my mark for the 2008 practice paper wasn't. I didn't think I would get 39/55 but I did. ****! Why so many silly mistakes?? It doesn't make sense... I'm supposed to be good at Maths! Two unit maths isn't supposed to do this to me!!