Hot Math How-Tos

How To: Solve rate-of-change problems with derivatives

Need to know how to use derivatives to solve rate-of-change problems? Find out. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to solve...

How To: Determine whether 2 triangles are similar in geometry

Looking for instructions on how to determine whether two triangles are similar in geometry? From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn ...

How To: Multiply and divide negative numbers in arithmetic

Need to know how to multiply and divide negative numbers in basic math? From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to multiply and ...

How To: Graph points using Cartesian coordinates

Need to know how to graph points in two dimensions using Cartesian coordinates? Learn how. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn h...

How To: Find the equation of trig functions by their graphs

Need to know how to determine the equations of trigonmetric functions by inspecting their graphs? Learn how. Learn how to use trigonometric functions to calculate the sides of a right triangle. Need to know how to solve a matrix-form linear equation in algebra? From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just f...

How To: Graph trigonometric functions

Learn how to graph the amplitude and periods of sine and cosine functions in basic trigonometry. Learn how to use trigonometric functions to calculate the sides of a right triangle. Need to know how to solve a matrix-form linear equation in algebra? From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your h...

How To: Find the sides of a right triangle with trig functions

Learn how to use trigonometric functions to calculate the sides of a right triangle. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to ...

How To: Convert between radians and degrees in trigonometry

Need to know how to convert between radians and degrees? Learn how. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to convert between r...

How To: Write a percentage as a decimal number

Want to know how to express a percentage as a decimal number or a decimal number as percentage? Learn how. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials...

How To: Increase a number by a percentage in basic arithmetic

Need to know how to grow a quantity by a percentage? Learn how. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to increase a number by ...

How To: Use the sine, cosine & tangent trigonometric functions

New to trigonometry? Learn how to calculate cosine, sine and tangent with this lesson. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how t...

How To: Solve a quadratic inequality in algebra

Need to know how to solve quadratic inequalities? From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn a system for solving basic linear inequali...

How To: Convert between mixed numbers and improper fractions

Need to convert mixed numbers to improper fractions and improper fractions to mixed numbers? Learn how. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, y...

How To: Solve advanced ratio problems in algebra

Need to know how to solve complex ratio problems in basic algebra? From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn a system for finding solu...

How To: Carry numbers when adding in basic arithmetic

Need to know how to carry numbers when adding in basic mathematics? Learn how. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to carry ...

How To: Solve multivariable linear equations

Looking for instructions on how to solve linear equations with multiple variables and constant terms? Look no further. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free ma...

How To: Solve linear equations in the form of AX+B=C

Need to know how to solve AX+B=C-form linear equations in algebra? From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn a system for solving line...

How To: Solve linear equations in matrix form (Ax = B)

Need to know how to solve a matrix-form linear equation in algebra? From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn a system for solving lin...

How To: Add consecutive integers in math

Want to know how to sum a series of consecutive integer numbers (e.g., 1+2+3+4+5)? You're in luck. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll...

How To: Solve quadratic inequalities by factoring in algebra

Looking for a guide on how to solve quadratic inequality problems? From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to find the right ans...

How To: Calculate the slope of a line in algebra

Looking for a guide on how to figure out the slope of a line in basic algebra? From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to calcul...

How To: Solve math problems containing fractional exponents

Looking for a guide on how to work with fractional exponents in basic math? From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to solve fra...

How To: Solve negative exponent problems in basic math

Looking for a guide on how to work with negative exponents in basic math? From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to solve simpl...

How To: Determine whether two fractions are equivalent in math

Looking for a guide on how to tell whether two fractions are rationally equivalent to one another? From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll...

How To: Factor and solve a quadratic equation in algebra

Looking for a guide on how to solve quadratic equations by factoring? From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to factor and solv...

How To: Find the greatest common factor of two numbers

Looking for a guide on how to calculate the greatest common divisor for two numbers? From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to ...

How To: Find the least common multiple (LCM) of two numbers

Need to know how to figure out the least common multiple or LCM of two given numbers? From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to...

How To: Calculate the area of rectangles and triangles

Need to know how discover the area of a triangle or rectangle? From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to find the area and peri...

How To: Add and subtract negative numbers in basic arithmetic

Looking for a guide on how to sum and subtract negative integers? From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to add and subtract ne...

How To: Add and subtract rational expressions in algebra

In this math tutorial, you'll be trained in the arcane art of adding and subtracting rational expressions by finding the common denominator. A skill many discard upon leaving middle school, it is used by the villians who operate under the acronym "SAT" to test those caught blank minded and whose minds are unrationalized.

How To: Simplify complex fractions in algebra

Being circuitous and using ample euphemisms has gotten many a politan elected by the dumb and hated by the knowing. Though embellishing speech is often preferred in jovial presidential debates, mathematicians prefer to cut out the fat and get straight to the point.

How To: Convert a simple decimal to a fraction

Fractions to decimals, decimals to fractions... it can get a bit confusing from time to time. That's why there are free videos out there to help you in your math weaknesses. In this video, learn how to easily convert a simple decimal to a fraction in just a few steps.

How To: Solve advanced rational equations in algebra

From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to find the partial derivative of how to solve more challenging rational equations in al...