The Skills module is a speed-and-accuracy drill for the moves the GMAT Focus Edition punishes you for being slow at. The on-screen calculator is gone for the Quant section, and the Critical Reasoning section is unforgiving of slow argument-mapping. The Skills module is where you build both reflexes — 10-question sets, a tight per-question timer, and a personal best that tracks your speed. Train the reflex here, then bring it back to Practice where you have more time to think.

A) Two Tabs, One Module

Pick the tab that matches the gap you are trying to close. Most students benefit from doing at least one set per day in each tab.

• Mental Math — arithmetic reflexes for the no-calculator Quant section. See the 12 categories below.
• Logical Reasoning — formal-logic drills (argument structure, conditionals, quantifiers, negation, claim strength) that build the reflexes CR needs. See the 7 categories below.

B) Mental Math Drills

Adaptive Practice focuses on reasoning, not arithmetic. The Mental Math tab is the opposite — it drills the arithmetic reflex under time pressure. Pick the category that matches the gap you are trying to close.

• Percentages — Fast 10/20/25% shortcuts, chained percentage changes, and the "10% trick" for estimating.
• Fractions — Simplifying, common-denominator, and fraction arithmetic without long division.
• Arithmetic Shortcuts — Multiplication tricks, the difference-of-squares, and distributive patterns.
• Squares — Squares of numbers ending in 5 (use the 25 / half-and-prepend pattern) and squares built by (a ± b)² expansion — e.g. 49² = (50−1)², 112² = (110+2)². Most sets land in the 10–125 range.
• Powers & Shortcuts — Small powers — 2ⁿ and 3ⁿ up to about n=4. The reflex is repeated multiplication without writing it out (double for 2ⁿ, triple for 3ⁿ).
• Roots — Square roots of perfect squares (√9, √16, √49, √64, √144, √169), recognizing Pythagorean triples inside √(a²+b²), and simplifying radicals (√50 = 5√2, √(16·2) = 4√2).
• Ratios — Scale a part-to-part ratio — given A:B = p:q and one value, find the other. The move is "one part = known value ÷ p", then multiply to get the missing side.
• Number Properties — Divisibility, factors, multiples, primes, and remainder patterns.
• Algebra Manipulation — Solve linear equations for x — isolate, divide, subtract. Most questions are one or two steps (3x=72, 2x+5=25, 7x=84). Also covers simple ratios (2x=3y → x:y) and a basic quadratic (x²=144).
• Mixed Elite — A mix of the above. The hardest sets. Use once the single-category sets feel easy.
• Conversion — Fraction ↔ percent conversion — 1/8 = 12.5%, 1/16 = 6.25%, 3/16 = 18.75%, 7/8 = 87.5%. Memorize the eighths and sixteenths; the rest falls out.
• Estimation — Round to the nearest 10/100 and approximate — e.g. 39 + 48 ≈ 40 + 50 = 90, 199 + 312 ≈ 200 + 310 = 510. Pick the closest answer, not the exact one.

C) Logical Reasoning Drills

Adaptive Practice tests whether you can read a 200-word argument, identify the gap, and pick the right answer in around two minutes. The Logical Reasoning tab speed-drills the formal-logic moves that underpin CR — argument structure, conditional equivalence, quantifier syllogisms, formal negation, claim strength. Pick the category that matches the gap you are trying to close.

• Argument Roles — Label each statement in a short argument (premise, conclusion, background, evidence, counterexample). Fast role identification is the foundation for every CR question type.
• Equivalent Rewrite — Convert a conditional or categorical claim into its logically equivalent form — "A only if B" ↔ "if not B then not A", "every A is B" ↔ "if A then B", "A whenever B" ↔ "if B then A". Same meaning, different shape; the trap is flipping only one side.
• Quantifier Chain — Given two categorical premises, pick the conclusion that must be true. You walk the quantifier ladder (all, most, some, none) to see which links hold — "all → some" always chains, "some → some" does not. The trap is letting "some" or "most" carry through "all".
• Assumption Type — Given an argument and a candidate assumption, classify it as necessary (negate it — does the conclusion die?) or sufficient (assume it — does the conclusion follow?). Necessary is the one CR almost always wants; sufficient is the one CR almost never does.
• Negation Drill — Produce the formal logical negation of a statement — "All A are B" → "Some A is not B", "Some A are B" → "No A are B", "must" → "might not", "never" → "sometimes doesn't". Building block for the Negation Test you apply to CR answer choices; that test itself is taught in the verbal guide.
• Must or Could — Distinguish conclusions that must follow from the premises from conclusions that could follow. Most wrong CR answers are "could be true" choices presented as if they were "must be true".
• Rank the Claims — Rank a stack of claims on a single strength dimension — either modal (definitely > probably > might > might not) or quantifier (all > most > some > none). The trick is keeping the dimension constant; mixing "all" with "probably" is the usual miss.

D) Starting a Set

Open Skills from the sidebar. Each tab shows its available sets as cards, grouped by category. Click a set card to open the start dialog.

The dialog has a slider for per-question time, ranging from 5s to 30s. Total time is shown live (e.g. 15s × 10 = 150s). The default is 10s for Mental Math, 15s for Logical Reasoning. Push down to 5–8s once a category feels automatic; push up to 20–25s if the moves are new to you.

If you have attempted the set before, your personal best is shown in the dialog. Beating it is the goal.

E) During a Set

• Read the prompt and answer choices, then commit. A wrong answer lets you try again, up to 2 attempts per question. The same question will not advance until you get it right or run out of attempts.
• The timer is per question, not per set. If you are stuck, take an educated guess before the timer runs out — a wrong answer with a guess still counts as "attempted" for the purpose of the set, and the answer will be revealed with a short explanation.
• After you answer correctly or run out of attempts, the question reveals the right answer and shows a tip card with the shortcut or reasoning move you should have used. Read the tip — that is the actual lesson in this module.
• After the last question, the summary page shows your score (correct / total) and your time used. Your personal best for the set is updated automatically if this run beat it.