The Rule of 72 - Doubling Time of an Investment

The Rule of 72: Annual Rate or Return Needed to Double Investment

Inflation and The Rule of 72: Time for Money to be Worth Half of its Value Under Inflation

Find the Percent of Change

Divide Fractions Using a Common Denominator

Find the Quotient of Two Percentages as a Percent

Related Rates: Find the Rate of Change in the Water Height as it Drains from a Right Circular Cone

SAT Math Prep: Find the Value of a Computer after 3 Years (Constant Rate of Decrease)

Metric Conversion Shortcut (Single Digit)

SAT Math Prep: Find an Average Cost Given a Ratio of Item Purchased by Two People

SAT Math Prep: Determine the Value of an Expression Given a Linear Equation

SAT Math Prep: Determine x if y = 2 and 49=(xy-3)^2

SAT Math Prep: Simplify an Expression to Determine a Difference of Coefficients

SAT Math Prep: Find a y-coordinate of a Point on a Line Given the Intercepts

SAT Math Prep: Given a Linear Equation in One Variable, Find the Value of an Expression

SAT Math Prep: Find a Base Angle of an Isosceles Triangle in a Diagram

SAT Math Prep: Simplify and Find a Difference of Complex Numbers

SAT Math Prep: Find a Missing Constant in Two Equivalent Quadratic Expressions

SAT Math Prep: Complete the Square on a Quadratic Expression

SAT Math Prep: Find an Equivalent Expression with Radical and Rational Exponents

SAT Math Prep: Given the Roots of a Cubic Equation, Determine the Factors of the Cubic

SAT Math Prep: Find the x-coordinate of the Vertex Given a Quadratic Function in Factored Form

SAT Math Prep: Which Ordered Pair Satisfies a System of Equations

SAT Math Prep: Determine a Function Value of a Rational Function

SAT Math Prep: Find the Interval of the x-coordinate of a Quadratic Function (Factored Form)

SAT Math Prep: Given Two Equivalent Quadratic Expressions, Find a Missing Constant M#1

SAT Math Prep: Given Two Equivalent Quadratic Expressions, Find a Missing Constant M#2

SAT Math Prep: Perform Synthetic Division to Find a Quotient

SAT Math Prep: Find x - y Given a System of Equations

Divisibility Rule for 3

Pattern Multiplying a 2 Digit Number by 11 (Sum of Digits Less than 10)

Divisibility Challenge: Find the Missing Digits

Squaring Numbers with Digits of 1

SAT Math Prep: Review Exponential Decay Function - Country's Declining GCP

SAT Math Prep: Interpret a Constant in a Function Modeling Population

Pattern Multiplying a 2 Digit Number by 11 (Advanced)

SAT Math Prep: Find a Percent of Minutes in Seconds

SAT Math Prep: Find a Missing Angle from a Diagram

Connect The Same Colored Dots without Intersecting Curves

The World Population Reaches 8 Billion!

Graph a Piecewise Defined Function

Evaluate an Expression Based Upon Two Equations

Simplify an Expression Using the Order of Operation: 8/2(2+2)

Find the Reciprocal of a Square root of a Fraction

Simplify a Square Root Expression Using Exponent Rules

Determine the Product to Two Square Roots

Does 0.999… = 1?

SAT Math Prep: Find the Center and Radius of a Circle Given an Equation of a Circle

SAT Math Prep: Determine x Given 3 Exponential Equations

SAT Math Prep: Given f(x+3) = 4x + 5, Determine f(x)

SAT Math Prep: Given f(x+3) = 4x + 5, Determine f(1)

The Monty Hall Problem: Switch Doors or Not?

SAT Math Prep: Find an Expression for the Area Between a Square and Circle

SAT Math Prep: Determine x from an Equation with Many Fractions

SAT Math Prep: Simplify the Sum of Exponential Terms

SAT Math Prep: Find the Area of the Shaded Region of a Rectangle

SAT Math Prep: Given an Equation, Determine the Value of an Exponential Expression (1)

SAT Math Prep: Given an Equation, Determine the Value of an Exponential Expression(2)

SAT Math Prep: Given an Equations, Determine the value of an Expression

SAT Math Prep: Simplify an Expression with Powers of i, the imaginary unit

SAT Math Prep: Determine the Length of a Side of a Right Trapezoid Using the Pythagorean Theorem

SAT Math Prep: Write an Equation from Works and then Determine 3x

Math Challenge: Simplify and Square Root Expression Using Factoring

Stick Multiplication 1: 15*13

Stick Multiplication 2: 23*16

Area of a Sector

Lattice Multiplication: 2 digit times 2 digit

Lattice Multiplication: 3 digit times 2 digit

The Most Beautiful Equation: Euler's Identity

Alternative Method to Add Fractions with Unlike Denominators

Trick Math Problem: Give the Cost of 2 Items and One is $6 More, How Much is the Other Item?

Find a Linear Function Value Given a Table Without the Function Value

Given an Ordered Pair of a Parametric Function, Determine the Function of x

Common Error: Simplifying Fractions

Can You Cut a Cake Into 8 Pieces With Three Cuts?

What 2D Shape Has Maximum Area? What 3D Shape has Maximum Volume?

Interesting Math Facts about Large Numbers

Interesting Math Facts: Four, One, Zero, and Temperatures

Interesting Math Facts: Forty, One, and Palindrome Numbers

Challenge: What Day Is It?

Determine the Fraction of a Square That is Shaded

How To Quickly Add 1 to 100

Exponential Equation Challenge

Square Root Equation Challenge

Equation Challenge: Solve an Exponential Equation with Square Roots

SAT/ACT Practice: Simplify Fraction Raised to Negative Rational Exponent

SAT/ACT Practice: Solve an Equation with a Complex Fraction

Write Numbers Using Scientific Notation

Converting Scientific Notation to Decimal Notation

SAT/ACT Practice: Area of Region in a Rectangle and Outside Circles

SAT/ACT Practice: Exponent Properties Challenge

SAT/ACT Practice: Evaluate a Rational Expression Using Exponent Properties and a Given Equation

SAT/ACT Practice: Given a System of Equations, Find the Value of an Expression

Solve an Equation With an Absolute Value Using Exponent Properties

Express a Interval Using an Inequality and Interval Notation

Find the Area of a Rectangle Inside a Right Triangle

Find the Value of a Logarithm Using a System of Equations

Find a Percent of Change: Increase in Price of Gas

Pi Day is March 14th! 3/14

Number Line Intervals Using Inequalities and Interval Notation

Date and Time 50 Hours after a Given Day and Time

Date and Time 56 Hours after a Given Day and Time

Find a Percent of Change: Decrease in Car Value

Equation Challenge: Solve a Rational Equation with a Complex Fraction

(Trig Review) Trigonometric Function Values Using a Right Triangle

Simplify an Expression: A Product of a Sum of x's

(Trig Review) Find the Perimeter of a 30-60-90 Right Triangle Given the Short Leg

(Animation) The Sum of the Interior Angles of Any Triangle

Determine the Area of a Shaded Region Inside of a Square

(Trig) Determine the Length of a Leg of a Right Triangle Given an Angle and the Hypotenuse

Geometry: Find a Missing Interior Angle of a Triangle

Area Challenge: Find the Area of a Polygon With Sides of Missing Length

Challenge: Evaluate an Absolute Value Expression

Evaluate the Cube of an Expression Given an Equation

Find a Missing Value Given an Average of Values

Find the Interior Angles of a Pentagon

Perimeter Challenge: Find the Perimeter of a Polygon with Sides of Missing Length

Challenge: Evaluate the Sum of Fractions with Square Roots

Find the Measure of a Missing Interior Angle of a Quadrilateral

Find a Missing Interior Angle of a Triangle Given an Interior and Exterior Angle

Absolute Value Expression Challenge

Find Consecutive Integers Given the Sum

Math Challenge: Find the Value of An Expression Given an Equation

Most Commonly Missed Exponent Rules (Product and Power to Power)

Algebra Review: Find a Missing Constant of Function Given a Function Value

Algebra Review: Determine a Difference of Function Values

Sequence Challenge: Find the Next Letter in a Sequence

Common Error: Simplify an Expression Using the Order of Operations

Challenge: Simplify an Expression with Percentages

Equation Challenge: Solve a Radical Equation

Exponent Challenge: Simplify an Sum of Exponential Terms with Exponents Raised to Exponents

Simplify a Quotient of Factorials

Determine the Fraction of a Square That is Shaded

Percent Challenge: 60% of 80 is What Percent of 200?

Product of Square Roots Challenge: Negative Radicands

Equation Challenge: Using an Equation in Two Variables to Find the Sum of Two Variables

Find the Measure of an Exterior Angle of a Triangle Using Given Information

Adding Integers Using a Money Analogy

One of the Most Beautiful Equations: Euler's Identity

https://youtube.com/shorts/p5UkPlMiGqEMake Equations True with Parentheses and Arithmetic Operations: Twos (Part 1)

Make Equations True with Parentheses and Arithmetic Operations: Twos (Part 2)

Make Equations True with Parentheses and Arithmetic Operations: Threes (Part 1)

Make Equations True with Parentheses and Arithmetic Operations: Threes (Part 2)

Make Equations True with Parentheses and Arithmetic Operations: Fours (Part 1)

Make Equations True with Parentheses and Arithmetic Operations: Fours (Part 2)

Make Equations True with Parentheses and Arithmetic Operations: Fives (Part 1)

Make Equations True with Parentheses and Arithmetic Operations: Fives (Part 2)

Make Equations True with Parentheses and Arithmetic Operations: Sixes (Part 1)

Make Equations True with Parentheses and Arithmetic Operations: Sixes (Part 2)

Make Equations True with Parentheses and Arithmetic Operations: Sevens (Part 1)

Make Equations True with Parentheses and Arithmetic Operations: Sevens (Part 2)

Make Equations True with Parentheses and Arithmetic Operations: Eights (Part 1)

Make Equations True with Parentheses and Arithmetic Operations: Eights (Part 2)

Make Equations True with Parentheses and Arithmetic Operations: Nines (Part 1)

Make Equations True with Parentheses and Arithmetic Operations: Nines (Part 2)

Determine Which Exponential Term is Greater: 5^22 or 3^33

The Butterfly Method to Subtract Fractions

Simplify Fractions Using the TI-84: Two Methods

ACT/SAT Math Prep: Determine the Price of a Phone Given Information

ACT/SAT Math Prep: Proportion with Mixed Numbers

Equation Challenge: Solve an Equations with a Complex Fraction

ACT/SAT Math Prep: Given the Sum and Ratio of Two Unknown Numbers, Find Their Product

Arithmetic Challenge: Make an Equation Try Using Addition, Subtraction, Multiplication and Division

The Butterfly Method to Add Fractions

ACT/SAT: Properties of Exponents Challenge

Alternative Method to Multiply When Multiplying by Nines

Number Pattern When Multiplying with 19

ACT/SAT Math: Determine the Ones Place Value of 4 raised to a Large Power

Pattern Challenge: Redefining Addition (Part 1)

Pattern Challenge: Redefining Addition (Part 2)

https://youtube.com/shorts/3hf35_hhnO8https://youtube.com/shorts/FU-S6PyN0bsHow Big is One Million? Numerical Approach

How Big is One Million? Time, Area, Volume

How Big is One Million? Distance and Money

Connect 9 Points Challenge

Make a 3D Design On Desmos Using Functions with Domain Restriction and Transformations

Equation Challenge: Solve an Equation Using Exponent Properties

Curious Calculation #1: The Answer is Always 3?

Curious Calculation #2: The Answer is Always 8?

Curious Calculation #3: The Answer is Always 37?

What is a Googol?

Where is the Missing Dollar?

If a Stock does Down 10% and Then Up 10%. Is it Up, Down, or Unchanged in Value?

If a Stock does Loses 10%, What Gain is Needed to Recover?

ACT/SAT Math: Simplify a Quotient of Radicals Using Rational Exponents

Easily Compare Two Fractions Using Cross Multiplication

ACT/SAT Math: Find the Sum of Coefficients of a Quadratic Function Given f(0) and f(1)

Equation Challenge: Solve 5^(log x)=x Using Logarithms

Arithmetic Challenge: Reposition One Stick to Make an Equation True

Another Way of Showing a^0 = 1

Curious Calculation: The Answer is Always 73!?

Equations Challenge: Solve x^2=2^x

Find the Value of an Expression Given a System of Equations

Logarithmic Equation Challenge

Quotient Challenge: What is 4/50%?

Subtracting without Exchanges with a Minuend with 0's

Why is x^0=1?

Can You Make Exactly 4 Gallons of Water From a 3 Gallon and 5 Gallon Container

Which Fraction is Closest to 1/2?

Equations Challenge: Solve x^(1/2) = x^(1/4)

Equivalent Expressions? log_2(4^3) and log_2(4)^3

Plotting Points on the Coordinate Plane

What is 50% Divided by 1/2?

Use Eight 8's and Addition to Make 1000

Evaluate 5 Plus 20 Divided by 1/2

Name That Math Formula

Are the Three Fractions Different?

Challenge: Find the Next Term in the Sequence

18th Century Riddle: Find Your Son's Age

18th Century Riddle: What Time Is It?

Frog Jump Challenge

Pi Product Notation

Math Challenge: Powers of 2 Equation

Reversing Percent Problems

Rounding to the Nearest Tenth

Rounding to the Nearest Whole Number (Ones)

Rounding to the Nearest Tens

Sigma (Summation) Notation

Stick Multiplication

Arithmetic Challenge: 8 Divided by 1/2 Multiple times

Equation Challenge: (sqrt(x))^x = x^(sqrt(x))

Equation Challenge: 8^2+4^3=8^(2x)

Equation Challenge: 2^10+2^10=2^x

Equation Challenge: 2^(5x)=sqrt(2)

What Does It Mean To Divide By a Fraction?

Negative Exponent Review

Arithmetic Challenge: 1/2 Divided by 1/2 Multiple Times

What is 500% Divided by 50%?

Negative Exponent Challenge: 10^(-3)+10^(-2)

ACT/SAT Math: What is 8^16+8^16+8^16+8^16?

Can This Equation Be True? 8 + 8 = 91

Complete the Square to Solve a Quadratic Equation

Math Challenge: Simplify a Quotient of Complex Numbers to a Power

Equation Challenge: Solve 2*3^9-k*3^8=4*3^8

Which is Larger? 3^75 or 2^100

Can You Simplify a Rational Expression As Much As Possible?

What is the Price In Terms of X After Two Discounts?

Solve a Quadratic Equation Using the Quadratic Formula

Math Challenge: Given (x+y)/(x-y)=9, Determine x/y.

Rational Equation Challenge: Can You Solve the Given Rational Equation?

Math Challenge: Simplify 2^22 * 3^33.

Common Errors When Simplifying Rational Expressions

Math Challenge: Given the Sum and Ratio of Two Numbers, Determine the Product of the Two Numbers

Math Challenge: If x^10 = 5 and x^9/y=5555, Determine 1/(xy)

Why a +/- When Solving x^2 = a?

Do You Know the World Population?

Do you Know the Derivatives of the Trigonometric Functions?

Do you Remember the Basic Logarithmic Properties?

Review: Power Rule of Differentiation (Part 1)

Review: Power Rule of Differentiation (Part 2)

Simplifying Square Roots: Common Errors

Do You Know the Top 5 Most Populated Countries?

Equation Challenge: Find the Value of an Expression Given an Equation

New! Desmos Now Has a 3D Graphing Calculator!

Factor a Difference of Cubes

Factor a Sum of Cubes

Can You Find the Differences of the Imaginary Numbers? (Simplify First)

Find the Percent of a Percent of a Number

Answering the Three Types of Percent Problems Using a Percent Equation

Estimate the Value of a Square Root (Ex 1)

Estimate the Value of a Square Root (Ex 2)

How Much Sooner Can You Pay off A Loan By Paying More? (TVM Solver)

Know Your Car Payment Before Shopping for a Car (TVM Solver)

Know What Car Price To Look For From The Monthly Payment You Can Afford (TVM Solver)

Fractions to Positive Powers

A Fraction to the Power of Negative One: (3/5)^(-1)

A Fraction to the Power of Negative Two: (5/8)^(-2)

A Fraction to the Power of One-Half: (4/25)^(1/2)

A Fraction to the Power of Two-Thirds: (8/27)^(2/3)

A Fraction to the Power of Negative One-Half: (9/16)^(-1/2)

A Fraction to the Power of Negative Two-Thirds: (27/125)^(-2/3)

Determine a Max Loan Amount from a Monthly Payment Using a Formula

Determine How Much Money Needed For Retirement Using a Formula

Savings Annuity: Compare $100/Month for 30 Years to $200/Month for 15 Years

What is 6+6+6+6*0?

Finding Trigonometric Function Values using a 45-45-90 Reference Triangle

Finding Trigonometric Function Values using a 30-60-90 Reference Triangle

Commonly Missed Work Problem: How Long to Complete a Job When Working Together?

Math Challenge: Simplify the Square Root of a Sum (Cambridge Interview Question)

What is the Square Root of x^2?

Geometry: Find Missing Lengths and Area Using Area Decomposition

Convert Decimals Less Than One To Fractions

Convert Decimals More Than One To Fractions

Product Rule of Differentiation Without The Chain Rule

Product Rule of Differentiation With The Chain Rule

Equation Challenge: Find All of the Solutions to x^4=16

381,654,729 is a Special Number!

3,816,547,290 is a Special Number!

Which is Larger? Square Root of 2 or Cube Root of 3

Most People Miss this Math Problem: Cost of Ball and Bat

Suprising Math Fact: The Difference of Consecutive Squares

Suprising Math Fact: The Difference of Consecutive Squares Proof

The Power Rule of Differentiation Review

The Power Rule of Differentiation Review: A Square Root Function

The Power Rule of Differentiation Review: A Cube Root Function

Differentiation of an Exponential Function (Base e) with the Chain Rule

Differentiation of an Exponential Function (Not Base e) with the Chain Rule

Differentiation of an Natural Logarithmic Function (Base e) with the Chain Rule

Differentiation of an Logarithmic Function (Not Base e) with the Chain Rule

Does 1 = 0.9999…? (Fractions)

Does 1 = 0.9999…? (Equations)

Does 1 = 0.9999…? (Infinite Series)

Divisibility Rule for 7

Common Divisibility Rules

How to Determine the Prime Factorization of a Number

An Interesting Math Pattern Involving the Number 9

Derivatives Using the Chain Rule Involving Sine

If I Pay More on a Car Loan, How Early Can I Pay off the Loan? (TVM Solver)

If I Pay More on a Home Mortgage, How Early Can I Pay off the Loan? (TVM Solver)

Logarithmic Challenge: Does Log_4(x)=1/2Log_2(x)?

What is Special About Numbers with an Odd Number of Factors?

The Vertical Line Test: Determine if a Graph Represents a Function

The Horizontal Line Test: Determine if a Function is One-to-One

Simplifying Fractions: Dividing Out Common Factors

Simplifying Fractions Using Prime Factorization

Definition of an Inverse Function

Find an Inverse Function Value Given a Function Rule

Find an Inverse Function Value Given a Linear Function

Common Simplifying Error: -4^2/2

Find the Vertex of a Quadratic Function in Standard Form

Vertex Form of a Quadratic Function: Find Vertex and Axis of Symmetry

Quadratic Function: Standard Form to Vertex Form (a=1)

Quadratid Function: Standard Form to Vertex Form (a not 1)

Arithmetic Challenge: Simplify sqrt(1/16)+150% to a Fraction

Arithmetic Challenge: Simplify sqrt(1/16)+150% to a Decimal

Arithmetic Challenge: Simplify the Square Root of a Sum