Silly mistakes in S3

Im sure this also applies to s1 but moreso focusing on section 3; how do i stop making silly mistakes?

When the pressure is off, and I’m reviewing the questions i can make calculations easier and get a lot of the questions correct. But at other, times usually when timed, i make the DUMBEST mistakes known to humankind. I have the correct reasoning even for very difficult questions, since ive been working at it hard for the past 6 months since sept sit, but i just make DUMB errors like forgetting to add something or i misread a number and get a factor of 10 off or even go AGAINST my intuition which what feels like 99% of the time i was correct in my intuition.

Any tips? I hope this will not only help me but others who struggle with this too. Thank you!