GMAT Quant Basics

If you are taking the GMAT and you are not comfortable with maths, either because you never liked it or because you have not used it since university, this is where to begin.

Fractions sit inside almost every GMAT Quant question. Any time you multiply and divide, you are working with a fraction whether it looks like one or not.

Decimals show up on the GMAT wrapped in notation that looks harder than it is. Most of the difficulty comes from three places: knowing which digit is which, moving the decimal point correctly, and rounding to the right place.

Percentages are among the most dangerous topics on GMAT Quant. Not because the maths is hard, but because there are three separate ways to get a question wrong that all look like small slips: confusing what you are taking a percentage of, misplacing a zero, and treating a percentage change like a percentage share.

Exponents are mostly a set of rules to apply correctly rather than maths to work out. The two places people lose marks are mixing up the add rule with the multiply rule, and mishandling signs when the base is negative.

Root questions look worse than they are. The symbols are unfamiliar, so people freeze on questions where the actual arithmetic is 2 × 2 × 2.

Equations on the GMAT are less about algebraic technique than about picking the right route quickly. The methods you learned at school work, and several of them are slower than what the exam rewards.

Inequalities behave like equations most of the time, and the exceptions are where the marks are won and lost. Three rules cover almost every mistake people make: when the sign flips, what you can add, and what a squared term hides.

This is the topic that unlocks a specific kind of GMAT question: the ones that give you no numbers at all, only relationships, and ask which statement is always true.

Divisibility questions are usually testing whether you can eliminate answer choices fast. The shortcuts for 2, 3, 4, 5, 8, 9 and 10 are worth knowing cold.