Also worth noting is at my test center, they specifically said that we could not erase these notepad (they don't provide you with any type of erasers). I didn't want to void my score by inadvertently erasing anything, so I just wrote small and made my pad last me through the quant section. If you need more, you're supposed to raise your hand and they bring you more... but the pad was more than enough for my Q section (I didn't use it for V, so if you're used to writing a lot for the V, consider getting a new pad during your break).
Also, make sure your marker works. I was lucky that mine worked during the Q.. but when I tried to use it for a few questions on the V, I found that it ran out of ink. This would have been a huge time waster if it had happened during the Q section.. so save yourself the drama and make sure it works ok.