Hot Math How-Tos

How To: Multiply Any Number by 11 with a Super Fast Mental Trick

Most of the time, when I’m bored during math class, I play with my calculator to satisfy my boredom. Recently, I've discovered that when multiplying any number by 11, 111, or any number similar to it, that it has a pattern (though I guess everything in math has a pattern). I don't know if this technique is original, because I didn't read anything about this. It's just mere observation. If it’s a tried and true technique, let me know.

How To: Find a data point (Xi) with the Z-Score formula

In this free video math tutorial, we learn how to use the Z-Score formula to find a data point (Xi) in statistics. With mathematics, as with anything else, not everyone progresses at the same rate. Stats is no exception. 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. Whether you need help finishing your homework or studying...

How To: Factor trinomials using the Berry factoring method

In this free video math lesson YAY MATH, we learn how to factor trionmials using the Berry method. With mathematics, as with anything else, not everyone progresses at the same rate. Algebra is no exception. 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. Whether you need help finishing your homework or studying for that next...

How To: Simplify expressions involving i in intermediate algebra

In this free video math lesson YAY MATH, we learn how to work with imaginary numbers in intermediate algebra. With mathematics, as with anything else, not everyone progresses at the same rate. Algebra is no exception. 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. Whether you need help finishing your homework or studying fo...

How To: Work with logarithms in intermediate algebra

In this free video math lesson YAY MATH, we learn about logarithms — what they are, how they work and how to solve math problems involving them. With mathematics, as with anything else, not everyone progresses at the same rate. Algebra is no exception. 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. Whether you need help fin...

How To: Do synthetic division in intermediate algebra

In this free video math lesson YAY MATH, we learn how to divide a polynomial by a linear factor (e.g., x - a) using synthetic division. With mathematics, as with anything else, not everyone progresses at the same rate. Algebra is no exception. 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. Whether you need help finishing yo...

How To: Divide two polynomials in intermediate algebra

In this free video math lesson YAY MATH, we learn how to divide two polynomials using long division. With mathematics, as with anything else, not everyone progresses at the same rate. Algebra is no exception. 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. Whether you need help finishing your homework or studying for that ne...

How To: Solve a system of equations with two unknowns in algebra

In this free video math lesson YAY MATH, we learn how to simultaneous equations — sets of equations with multiple variables — in basic algebra. With mathematics, as with anything else, not everyone progresses at the same rate. Algebra is no exception. 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. Whether you need help fini...

How To: Factor a trinomial by GCF then grouping method

This is a video tutorial in the Education category where you are going to learn how to factor a trinomial by GCF then grouping method. For example how to factor the trinomial 6r(squared) – 28r + 16. The first thing is to get the greatest common factor (GCF) of the numbers. So, GCF of 6, 28 and 16 is 2. The trinomial can now be written as 2{3r(squared) – 14r + 8}. To factor by grouping, see the trinomial as the general formula of ar(squared) + br + c. To factor this, you got to look at the...

How To: Use probability to predict weather

In this video, we learn how to use probability to predict weather. Probability is the chance of something happening. If you want to know what the weather is going to be like, you can look at the weather report and see what each day is going to do throughout the week. Ask yourself what the probability is that the weather will be cloudy, judging from what the current work week weather is. First, figure out how many days there are total and then find out how many are cloudy versus how many are s...

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: Dissect the geometrical quadrilateral trapezoid

If you've ever had problems with trapezoids in the past, this math lesson should clear some things up. A trapezoid is a geometrical shape, a quadrilateral, that has only one pair of parallel sides. Outside of the US, it's referred to as a trapezium. Yay Math breaks down the properties of trapezoids, including the isosceles trapezoid, the legs of the trapezoid and the median of the trapezoid.

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: Calculate square roots on paper the easy way

Perhaps not as easy as using a calculator, but easy nevertheless! 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 find square roots by hand.

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.