Number & Quantity - Overview

The Number & Quantity domain focuses on numerical reasoning, operations, proportional relationships, percents, units, exponents, radicals, and number properties.

These skills form the foundation for many ACT Math questions and often appear throughout the exam in real-world contexts.

TipWhat You’ll Learn

By working through this domain, you’ll learn how to:

  • Work confidently with numbers and operations
  • Solve ratio, rate, and percent problems
  • Convert between units
  • Apply exponent and radical rules
  • Understand scientific notation
  • Use arithmetic and geometric sequences
  • Interpret numerical relationships in context

Course Structure

Topics in this domain include:

  • Numbers and operations
  • Order of operations
  • Fractions and decimals
  • Ratios and proportions
  • Rates and unit conversions
  • Percents
  • Exponents
  • Scientific notation
  • Radicals
  • Sequences

ACT Number & Quantity Tips

  • Estimate before calculating when possible.
  • Watch units carefully.
  • Convert percents to decimals early.
  • Learn exponent and radical rules thoroughly.
  • Check whether answers are reasonable.

Assess Your Progress

After completing the lessons, reinforce your understanding through:

  • Lesson practice questions
  • Unit assessments
  • ACT Domain Tests
  • Full-Length ACT Practice Tests

Select a topic from the sidebar to begin.