So Many Careless Mistakes

Aiyo, so many careless mistakes in my math...i can get 31/40..but one wrong calculation make my results to 21/40...da*n it!!! Haih, why so careless??? Always like that...why didn't I change? Stupid me....Argh!!!!So easy question also wrong...NVM!! Do well in finals then I'm through with the math!! HAHA!!