How To Be A Math Genius is now available.
Learn tricks like how to calculate a date's day of the week, how to multiply two three-digit numbers, how to test divisibility, and how to divide accurate to a large number of decimal places!
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App Contents:

(contents shown in black are available in the app for free)

(contents shown in red are available in the app through In-App Purchases)

  • Instructions and Glossary
  • Multiplying Two Numbers
    • Method 1: Slide Method
    • Method 2: Stretch Out Method
    • Method 3: Add First Method
    • Method 4: Straight Down Method
    • Method 5: Proportional Stretch Out Method
  • Squares
    • Method 1: Double First
    • Method 2: Minus Half Estimate, Times Twice Estimate
    • Method 3: Square Estimate First
  • Almost Round Multiple Method
  • 12 Multiplication Table
  • Multiplying Three Numbers
  • Cubes
    • Method 1: Normal Three-Way Method
    • Method 2: Change To Consecutive Numbers
    • Method 3: Expanded Polynomial
  • Checking Your Work
    • Divisibility Test
    • Alteration Test
  • Division
    • Expressing Quotient as Integer and Remainder
    • Expressing Quotient as Decimal
  • Decimal To Fraction
  • Divisibility Rules
  • Days Of The Week
  • Adding Many Numbers
  • Counting
    • The Middle
    • Mark Every 5
    • Checkpoints
    • Draw A Line
    • Arrange Into Triangles Or Squares
  • Special Cases
    • Multiplying By Multiple Of 9
    • Multiplying By Multiple Of 11
    • Multiplying By 143
      • Method 1: Divide By 7 First
      • Method 2: Separate Hundreds Place
      • Method 3: Multiply By 1,001 First
    • Multiplying By A Number Ending In 5
    • Same Tens Place, Ones Place Adds To 10
    • Midpoint Divisible By 10
    • Multiplying Numbers Close To 100
    • Adding Consecutive Numbers
    • Adding Almost Consecutive Numbers