Hot Math How-Tos

How To: Write equations in pre-Algebra

This is a video tutorial in the Education category where you are going to learn how to write equations in pre-Algebra. Write an equation that represents the following sentence and then solve the equation. The product of n and 6 is 12. That's n multiplied by 6 or 6n = 12. We want to solve our equation for n. That is we want to get n all by itself on the left hand side. Since n is multiplied by 6, we got to divide both sides by 6. So, we get 6n/6 = 12/6. On the left hand side of the equation, 6...

How To: Do operations with radical expressions

Radical expressions are those in which the radical symbol (under root sign denoting the square root or the nth root) is present (either multiplied or added). Solving these is a bit tricky, but involves similar algebraic maneuvers in a different way.

How To: Find a regression line in statistics

Learn how to solve statistics problems that require you to find the regression line. Whether you need help studying for that next big stats text or just a hand finishing your homework, you're sure to be well served by this four-part free video math lesson from Salman Khan.

How To: Compare population proportions in statistics

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. With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to compare population proptions in stats.

How To: Solve population proportion problems in statistics

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. With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to solve pop. proportion problems in stats.

How To: Compare population proportions in statistics

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. With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to compare population proportions.

How To: Calculate the confidence interval for difference between means

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. With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to find the CI for the difference between means.

How To: Calculate the sampling distribution of difference between means

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. With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to find the sampling distribution for the difference between means.

How To: Compute a square root using the geometric method

With mathematics, as with anything else, not everyone progresses at the same rate. Happily, in the age of Internet video tutorials, this isn't a problem. Those who progress quickly can go beyond what's being taught them and those who are struggling likewise have all the time in the world to catch up. With this free video math lesson, you'll learn how to calculate the value of a square using using geometry.

How To: Use the divisibility rule to test if a large number is divisible by 3

If you're looking for an easy way to determine if a number is divisible by 3, then look no further than the divisibility rule. It's a shorthand way to tell if any given number can be divided by 3, without actually performing the division. Take the number in question, and if the sum off all the digits is divisible by 3, then the original number will be, too. There are four examples in this math video.

How To: Find the variance of differences of random variables in statistics

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. For all of the details, watch this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, we learn how to calculate the variance of differences of random variables.

How To: Do hypothesis testing with a large sample proportion in statistics

Learn how to do large-sample-proportion hypothesis testing in stats! 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. For all of the details, watch this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials.

How To: Calculate a t-statistic confidence interval for a small sample size

Want to find the value of a t-statistic confidence interval for a small sample? This clip's your ticket. 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. For all of the details, watch this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials.

How To: Do a small-sample hypothesis test in statistics

Need a hand figuring out how to do small-sample hypothesis testing in stats? 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. For all of the details, watch this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials.

How To: Calculate Type I (Type 1) errors in statistics

Need a quick primer on how to solve type-1 error problem in stats? Let this video be your guide. 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. For all of the details, watch this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials.

How To: Work with z-scores and t-statistics in statistics

Learn about the difference between z- and t-statistics with this video guide. 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. For all of the details, watch this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials.

How To: Use one-tailed and two-tailed tests in statistics

Can't make heads or tails of one- and two-tailed tests? Never fear. This stats lesson will teach you everything you'll need to know. 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. For all of the details, watch this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials.

How To: Construct a small sample size confidence interval using a t-distribution

Learn how to build small sample size confidence intervals using t-distributions. 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. With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to construct a small size sample confidence interval using t distribut...

How To: Calculate mean and variance for a Bernoulli distribution

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 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 calculate mean and variance for a Bernouilli distribution.

How To: Find sample distribution in statistics

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 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 calculate sample distribution in statistics.

How To: Calculate mean & variance when given a Bernoulli distribution in statistics

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 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 calculate the mean and variance of a Bernouilli distribution.

How To: Calculate the confidence interval in basic statistics

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 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 calculate a confidence interval in basic statistics.

How To: Find a 95% confidence interval for a proportion in statistics

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 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 a 95% confidence interval in statistics.

How To: Multiply decimals together

In this tutorial we learn how to multiply decimals together. Start off by ignoring the decimal points on the equation and just imagining you have normal numbers. Then, multiply the two numbers that you wrote down together. Once you figure that out, it will be time to reintroduce the decimals. Look at the place the decimal is in each number in the beginning equation. Then, add the decimal places together between each of them. From here, place the decimal on the end of the answer you came up wi...

How To: Graph an equation

In this video, we learn how to graph an equation. First, pick a point out of the equation and see if it's a solution to the equation. This equation shows where two lines cross in the math problem. See if the two coordinates are part of the line that is on the equation. The two numbers are going to be the 'x' and 'y' that you plug into the equation. Once you have these written out, you will be able to graph them using the coordinates on the graph. Once finished, you will have graphed the equat...

How To: Multiply and simplify square roots

In this tutorial we learn how to multiply and simplify square roots. When you multiply square roots, you will first need to put them under one radical. From here, you will need to factor out what you have. Once you find a perfect square, find the square root of it. You can either write these as all separate equations or pull the perfect root on the outside of the other parts of the equation. Do the math until you find what you are left with. From here, you can do basic math to find what's lef...

How To: Graph a circle

In this tutorial, we learn how to graph a circle. When given an equation to graph the circle, you will first need to find the vertex of the circle. Once you find this, you can use those coordinates to mark the vertex on the graph. Follow the negatives and positives to go up, down, left, and right on the graph. Next, you will need to find the 'r' value of the equation. After this, you will use this to continue to graph the rest of the points around the vertex. When finished, draw the outline o...

How To: Find the volume of a swimming pool

In this video, we learn how to find the volume of a swimming pool. To do this, you will first need to find the measurements of all the sides that are on the pool. After this, you will plug in the measurements that you found into the equation to find the volume. This equation is: V=AH, volume= area(height). So, plug in the area and the height to the equation for A and H and then multiply these two together. Once you do this, you will find the answer! Don't forget to label the units on the fina...

How To: Subtract decimals

In this video, we learn how to subtract decimals. If you can subtract using basic numbers, then you will be able to subtract decimals. First, you will line up the tens and the other units of the numbers. Once this is finished, you will start to take away the top number from the bottom number. Borrow from the number to the left if you need to, then write down what you are left with on the bottom. Once you come up with your number, make sure you place in the decimal point where it goes. All you...

How To: Subtract rational expressions

In this video, we learn how to subtract rational expressions. To start, you will need to find common denominators. To do this, factor out the denominators in the fractions on both sides of the equations. Now you need to build the lowest common denominator for these two fractions. To do this, take the first denominator and take whatever is missing from the second. After you do the math for this, you will build new fractions with the common denominator as the denominator. Leave the denominator ...