Numbio is a mental math trainer for standardized tests. Timed drills on the arithmetic every quant section leans on (percentages, fractions, ratios, powers and estimation) free up minutes for the questions that need thinking. Built-in chapters cover GMAT, GRE, SAT and CFA shortcuts. No ads, no calculator.
Practice the math behind these exams:
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Quant without the calculator
The GMAT’s Quant section gives you no calculator, and the GRE’s on-screen one costs a click for every step. Drill percentages, fractions, exponents and large numbers until the arithmetic takes seconds and your time goes to the reasoning.
Train to the exam clock
Quant sections give you two minutes a question or less, and arithmetic shouldn’t eat most of it. Set a pace target, like 3 seconds per exercise, and a clock runs on every problem. Free one-minute tests with leaderboards show how fast you really are.
Shortcuts for your exam
The Textbook has a chapter for each major test: GMAT Shortcuts, GRE Strategies, SAT essentials and CFA Methods. Short articles cover the patterns that come back every sitting, like combined work rates, net percentage change and remainders, and they’re free to read.
Find what slows you down
After a few sessions, AI Picks spots the problems that cost you the most time and suggests a trick to fix each one. Every test score is charted, and you can see how your speed ranks against other players.
The math every quant section is built on
Drills for each type of test math, plus the tools that get you to exam pace.
Percentages
Percent change, discounts and 15% of 240.
Fractions
Simplify, compare, find GCD and LCM.
Powers and roots
Squares, exponents and square roots.
Equations
Solve for x without writing it out.
Rule of three
Ratios and proportions in one step.
Estimation
Close answers count, to train fast rounding.
Word problems
Reading and reasoning, as on the real test.
Exam chapters
GMAT, GRE, SAT and CFA shortcuts.
Pace targets
A clock on every question, 1 to 60 seconds.
Save Your Minutes for the Hard Questions!