Hot Math How-Tos

How To: Remember "greater than" & "less than" symbols

This video shows you how to easily remember "greater than" and "less than" math symbols. The first thing you have to remember is that "less than" symbol looks like the letter L ("less than" symbol is "<"). When you see this sign, remember that < looks like L and means "less than". The other symbol, "greater than" does not look like the letter L, therefore it cannot be "less than" and it's easier to remember. The "greater than" symbol is ">". That's it! Good Luck!

How To: Divide small numbers by big numbers

This is a mathematical educational video on how to divide a small number by a larger number. You are aware that it is easy to divide a larger number by a small number. For example, if you want to divide 379 by 9 it is easy to do so. But if you have to divide 9 by 379 it is a bit difficult. You have to add a zero and see if you can divide. You need to add one more zero so that you can divide 900 by 379. But you should know that the answer would start like this 0.0 as we have added 2 zeros alre...

How To: Use ">" (greater than) and "<" (less than) symbols

In this video the author explains how to identify the less than (<) and greater than (>) symbols and when to use them. She explains to us to relate the numbers to animals stating that the smaller numbers are smaller animals and bigger numbers are bigger animals. Now she tells us to imagine that smaller animals are eaten up by the larger animals. So she shows a smaller number comes on the left side of '<' sign and bigger number comes on the right side of '<' sign stating that the bigger number...

How To: Do long division without a calculator

This video shows you step by step how to do long division without the use of a calculator. The video shows viewers two different ways to solve a division problem. It first shows how to do the problem the traditional way, then it shows how to do it according to the long division process. The long division process is where you write the whole division, multiplication, and subtraction process out showing all your work. Long division is mainly used when dividing large numbers. There are three com...

How To: Calculate the area of a parallelogram

Calculating The Area Of A Parallelogram A parallelogram is a 4-sided shape formed by two pairs of parallel lines. Opposite sides are equal in length and opposite angles are equal in measure. To find the area of a parallelogram, multiply the base by the height. The formula is:

How To: Find the slope of a line given 2 points with fractions

In this video tutorial the instructor shows how to find the slope of a line given two points with fractional values. To do this first name your two points as point 1 with coordinates as x1, y1 and point 2 with coordinates x2, y2. Then substitute the values in the equation of the slope which is slope m = (y2 - y1) / (x2 - x1). Now all you have to do is simply the fraction after substituting the point values. Be careful about the signs while substituting in the formula. Now finally after solvin...

How To: Figure out the domain & range of a piecewise function

Need to calculate the domain and range of a graphed piecewise function? Learn how with this free video 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).

How To: Calculate a limit by getting a common denominator

This video explores how to get the limit by getting a common denominator. When you try and plug in a limit, for example when the denominator goes to zero, you can get yourself into a situation where you get the answer (0/0) which is mathematically irrelevant. To solve this problem, you must find a common denominator and split the problem up into its various parts. By setting common denominators in the numerator, you can then flip the fraction around allowing you to properly calculate the limi...

How To: Find the area of an oblique triangle using formulas

In this tutorial the instructor shows how to find the area of an oblique triangle using different formulas. To find the area of an oblique triangle there are different formulae. The first formula to calculate the area of a triangle is area A = (1/2) * a * b * Sin(C), where a and b are the lengths of the two sides of the triangle and C is the value of the angle of the triangle that lies in between the two sides a, b. Now substitute these values in the given formula to find the area if you have...

How To: Find the formula of a piecewise function given a graph

This video shows how to find the formula of a piecewise function when given a graph. The first step is to write a definition for the graph, which is done by identifying the different domains shown in the graph. The second step is writing formulas for each domain specified by the lines in the graph. The point-slope formula is used to identify the slope and y-intercept for the leftmost domain, which has a sloped line. A point and horizontal line make for simpler equations in the other pieces of...

How To: Find the slope from a set of points

To find the slope of a line you must have two points and then you must plug in the two points into the slope formula. The slope formula is m= y2-y1 over x2-x1. If the slope is a fraction be sure to reduce to the lowest. Remember if a number is divided into zero it is zero, if zero is divided into the number it is undefined. A calculator can help one remember this. Horizontal lines have slopes and vertical lines do not. Drawing the lines on a graph can help you see the actual slopes and which ...

How To: Solve problems involving 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 answers to rational equation problems in algebra.

How To: Identify characteristics of a sample during a survey

To identify characteristics of a sample in your survey, there are many factors to consider of your samples. The first four characteristics you need to focus on are gender, age, income level, and education level. All four of these characteristics must be proportional to that of the population. You also need to consider the geographic location. Only take samples from the immediate geographical area. Finally, an important characteristic of the survey is the sample size. You do not want to ask to...

How To: Convert fractions to percents in two steps

This video shows you how to easily convert fractions to percents. You can convert fractions to percents in 2 easy steps. The first step is multiplying the fraction by 100 (e.g.. your fraction is 3/5; 3/5 x 100 = 3/5 x 100/1 = 300/5). The second step is reducing the fraction, when possible (e.g.. 3/5 x 100/1 = 300/5 = 60). Don't forget to add the percent sign (%)(you obtained 60%). That's it! Good Luck!

How To: Find and sketch the domain of a multivariable function

Looking for a primer on how to find and sketch the domain of a function z = f(x, y) in calculus? Learn how with this free video calc 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).

How To: Calculate probability in "at least one" problems

Calculating probablities can be used to help us make decision. PatrickJMT explains how to calculate probability in an "either A or not A" scenario. The probability of A plus the probability of not A is equal to one. Therefore, the probability of A is equal to one minus the probability of not A ; P(A)= 1 - P(not A). The probability of a major earthquake in San Francisco over a period of time is used as an example. The probablity of an earthquake of a magnitude of 7.5 or greater in San Francisc...

How To: Evaluate square roots

This is the video about how to evaluate square roots. The square root of a number is a number that you can square to get it, that is, a number that you can multiply by itself to get the number. So, 2 is a square root of 4, because 2 x 2 = 4, and 3 is a square root of 9, because 3 x 2 = 9. (-2) x 2 is also 4 and (-3) x 2 is also 9. Numbers that have square roots always have two, a positive one and a negative one, but the square root symbol means only the positive one, so we can have one answer...

How To: Find the 100th term in a sequence

Need to find the nth term in a given arithmetic sequence? See how it's done with this free video math lesson. Need help finding the 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 seri...

How To: Find extra points for a parabola (quadractic equation)

This is a mathematical educational video on how to find extra points for a parabola. In the first two examples there is no need for finding extra points as they have five points and have zeros of the parabola. In example 3 we need to find extra points. The equation is y=4xsquare-4x+4. You can take x= -1 and get the value for y. You will get a point now. Similarly you can substitute -2 for x in the same equation and get the value for y. Now you get another point. Now you can draw the parabola.

How To: Subtract mixed numbers with borrowing

This video teaches you to subtract mixed numbers with borrowing. Consider 2 mixed numbers. For example 8 and 2/7 and the other 5 and 4/5.You have to subtract 5 and 4/5 from 8 and 2/7. First you have to convert the fractions to their common denominator. To equate the denominators of these two fractions you have to multiply the first denominator with the numerator and the denominator of the second fraction and also multiply the numerator and denominator of the first fraction with the denominato...

How To: Find the standard deviation with the Z-Score formula

In this tutorial, we learn how to find the standard deviation with the Z-Score formula. First, take your problem and write it out one by one underneath each other. Then, you will need to substitute the numbers in for the variables that are in the problem. Once you do this, you will follow the basic rules of math to find out what the answer to the problem is appropriately. Once you have done this, finish off the problem to find the answer, then you will have found the standard deviation using ...

How To: Do long division with decimals

Video Nerd thinks that when your doing long division with decimals you should first take out the decimal. Write the number as if it didn't have a decimal. For example if the problem was 12.5 divided by 5 then you will just use 125 and divide that by 5. Next divide the first digit of the dividend by the divisor an write the number up top. Next you multiply, after your done multiplying the numbers subtract, and when your done subtracting the numbers drop the reaming numbers in the dividend down...

How To: Write the equation of a circle in standard form

Here you'll be shown how to take the equation of a circle, and convert it into standard form. Also, it will be explained just what standard form is, while running through the process of conversion. You'll be able to use techniques to quickly work off the numbers on the equation, one by one, until it's simplified enough to understand. Complicated algebra functions become much simpler when you see these easy to use techniques, that will help you rearrange the equation into a form that is actual...

How To: Find the area of a circle when you know the diameter

In this video, it is shown how to calculate the area of a circle where the diameter is given. The formula for calculating the area of a circle is pi multiplied by square of radius. Radius is actually half of the diameter. In this video, the diameter is given as 10.6 meters. Hence, the radius will be half of 10.6 which is equal to 5.3 meters. Now, to find the area we shall multiply pi with the square of 5.3. Square of 5.3 is 28.09. If we multiply 28.09 with pi we shall get the area of the circ...

How To: Factor trinomials with 2 variables & GCF by grouping

In the video, the process of factoring trinomials is described. A trinomial that cannot be easily factored in its original form is shown. It is simplified by pulling out the greatest common factor. After that, a trinomial that is easier to factor is shown. Next, the simplified trinomial is broken up into four terms so that factoring by grouping can be done. Once again, a common factor from each pair is taken so that two binomials are created. Once the greatest common factor is added back with...

How To: Find the domains of rational expressions in algebra

Learn how to find the domain of 3 different rational expressions that have quadratic expressions in the denominator with this free video algebra 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 study for that next big test).

How To: Find density using the water displacement method

To find out the density of any given object there is a simple equation, mass divided by the volume equals the density. In this video a lady is showing how to get the volume of three objects using water. First the objects are measured on a scale to find out how much they weigh, the mass. Next each one of the objects is placed into a measured amount of water to find out the volume. Before you place the object into the water you will want to know just how much water in there. That way when the o...

How To: Calculate percentage

Not sure exactly how to calculate a twenty percent tip for your waitress? Or how about how to figure out how much less your cost will be with that thirty percent off tag? Use these steps to calculate percentage, without a calculator.

How To: Identify the numerical coefficient of a monomial

In this tutorial the instructor discusses about the numeric coefficients that we come across while we work with polynomials. He goes on to discuss the numerical coefficient of a monomial stating that it is the number that is present before the variable in the monomial. He states that the numerical coefficient can also be negative or if there is no number present in front of the variable, it indicates that the numerical coefficient is one. This video helps in understanding what the numerical c...

How To: Solve & find the least common multiple

This is a mathematical instructional video on how to find the least common multiple. Let us now find the least common multiple for 25, 100, 18. This can be written as 5 square, 2 square multiplied by 5 square, 2 multiplied by 3 square. The highest factor in these numbers are, 5 square, 2 square and square. If you multiply 5 square with 2 square and 3 square you will get the final answer as 900. This is the least common multiple of 25, 100, and 18. This method is explained very clearly in this...

How To: Graph by using an X-Y table

In this video the author shows how to graph using an X-Y table. He shows how to do this with a sample equation. He builds a table of x, y values where he takes sample values for x like -1, 0, 1 and now he substitutes these values in the equation of the line and obtains the corresponding y values. Now finally he has an x, y value table which now he shows how to plot it on a coordinate plane. He plots all the three pairs on the graph and connects them with a line finally obtaining the resultant...

How To: Calculate azimuth in trigonometry

Azimuth is simply the angle of an object in the sky along the horizon. Yes, it's spherical trigonometry but it's not difficult! Check out this video and in just a few minutes you will be able to solve azimuth problems on your own.

How To: Find the area of triangle using fraction measurement

This video demonstrates the way to find the area of a triangle using fraction measurements. The person presenting this video first writes the actual formula for calculating the area of the triangle. The formula is: the area of the triangle denoted by ‘A’ is equal to half of ‘b’ times ‘h’ where ‘b’ and ‘h’ are the base and height of the triangle, respectively. Now, to make it into fractions, he writes ‘b’ and ‘h’ over ‘1’. Then he asks you to calculate “what is one times ‘b’ times ‘h’” which i...

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