One of the easiest ways to save time on the GMAT is to get comfortable calculating percentages in your head.
Many test-takers waste valuable seconds writing down calculations that could be done mentally. On a timed exam like the GMAT, those seconds add up quickly. Instead of setting up formulas or filling your scratch pad with arithmetic, train yourself to recognize simple percentage building blocks and combine them mentally.
A good way is to break percentages into simple pieces:
- 50% = half
- 10% = move the decimal one place to the left
- 1% = move the decimal two places to the left
For example:
30% of 12030%=10%+10%+10%10% of 120 = 12
12 + 12 + 12 = 36
33% of 12033%=30%+3%30% = 36
3% = 3*1% --> 1% of 120 = 1.2 --> 3*1.2 = 3.6
36 + 3.6 = 39.6
15% of 20015%=10%+5%10% = 20
5% = half of 10% = 10
20 + 10 = 30
The goal isn't just to get the right answer — it's to get it efficiently. The less time you spend on arithmetic, the more time you can dedicate to the reasoning and problem-solving skills that the GMAT is actually testing.
Small mental math shortcuts can lead to big gains on test day.