### How To: Find a number given Its percent

This how-to video is about how to find a number when its percent is given. This video is really helpful and effective in finding the number when the percent is given, the following steps are explained in the video to find the number when its percent is given:

### 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: Convert between diameter and radius

To convert between diameter and radius just follow a few steps. Sometimes we aren't given the number directly so first we need to find the diameter.

### How To: Calculate Faster Than a Calculator

When you need to crunch numbers quickly — and I mean really quickly — there's a cool method you can use to multiply two numbers together in just a few seconds.

### 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: Convert decimals into fractions

In this simple tutorial the author shows the basic arithmetic operations like converting a terminating decimal into a fraction. He says that the complexity depends up on the number we are converting. He asks us to imagine the decimal as a fraction with an imaginary denominator of value one. Now he intends to remove the decimal in the numerator by moving it to the right of the number and he tells us to similarly move similar number of decimal places in the denominator to maintain the original ...

### 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: Find the Percent Given Two Numbers

Whether you're shopping for deals, need help with a little math, or any number of other occasions, it's a valuable skill to know how to quickly figure out a percentage given two numbers.

### How To: Find a slope of a straight line with: Ax + By + C = 0

In this video the instructor shows how to find the slope of an equation which is in the form Ax + By + C = 0. He says that the formula to find the slope of a line in the above form is slope m = -A/B, where A and B are the numeric constants of the variables x and y in the given equation. He goes on and further shows how to do this with a couple of examples. He shows how to reduce any equation into the general form and how to apply the slope formula then. This video shows how to find the slope ...

### How To: Solve equations with the order of operations

In mathematics, the order of operations define the priority in which complex equations are solved. The top priority is your parenthesis, then exponents, followed by multiplication and division, and finally addition and subtraction (PEMDAS). This video tutorial demonstrates the order of operation with various examples and explains the associated methodology. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autod...

### How To: Calculate percent composition for chemistry

To calculate percentage composition we will take the example CO2 it stands for Carbon-Di-Oxide. It is the composition of Carbon and Oxygen. We have one carbon and its weight is 12.01 and 2 oxygen. So, we will multiply 2 with 16.00 which is the weight of the oxygen.

### How To: Find the area of a triangle when given 2 sides & angle

This video shows you how to easily find the area of a triangle when you know the length of 2 sides and the angle between them. The first thing you have to do is mark the sides of the triangle by a, b, c, where a is the side between A and B, b is the side between B and C and c is the side between C and A. If you know 2 of these 3 sides an you know the angle between them you can find the area of the triangle very simple: Area= (a x b x sin c)/2, where a, b are the two sides and c is the angle b...

### How To: Determine the age of a fossil using carbon-14

If you have a fossil, you can tell how old it is by the carbon 14 dating method. This is a formula which helps you to date a fossil by its carbon. If a fossil contains 60% of its original carbon, how old is the fossil? The half life of carbon 14 is 5600 years. That means this is how long it takes for half the nuclei to decay. After 5600 years, if we start with a gram, we end up with half a gram. This rather complex formula shows you how to solve this puzzle using accepted scientific methods.

### 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: Solve for the missing ratios or proportions

In this video the tutor shows how to solve the missing ratios or proportions. He explains it with an example, where a number in one of the ratios is missing and he intends to find this value. He shows the example of cross multiplication, where you multiply the values on the either side of the equation diagonally and finally solves the equation which results in the value of the unknown value. This is an introductory video explaining how to use rations and proportions to find missing values.

### How To: Factor a trinomial with negative leading coefficient

In this video the instructor shows how to factor a trinomial with negative leading coefficient. Most of the students are confused when they have to factor a trinomial with a negative leading coefficient. But there are many ways to solve these kind of problems as shown in this video. One way you can do is that take out the greatest common factor (GCF) of -1 from the equation. So pulling the -1 gives you the original trinomial with all the signs of the terms changed. Now go on and factor the ne...

### How To: Find outliers using the Z-score method

If you use Microsoft Excel on a regular basis, odds are you work with numbers. Put those numbers to work. Statistical analysis allows you to find patterns, trends and probabilities within your data. In this MS Excel tutorial from everyone's favorite Excel guru, YouTube's ExcelsFun, the 49th installment in his "Excel Statistics" series of free video lessons, you'll learn how to find outliers with the +/- 3 Z-score rule and the ABS function. See how to do a box plot by hand and in Excel. For th...

### 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: Estimate probabilities with the empirical rule

Learn how to use the empirical rule (or 68-95-99.7 rule) to estimate probabilities for normal distributions 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 finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of fre...

### How To: Write a sum/difference of logarithms as a logarithm

To write the sum or difference of logarithms as a single logarithm, you will need to learn a few rules. The rules are ln AB = ln A + ln B. This is the addition rule. The multiplication rule of logarithm states that ln A/b = ln A - ln B. The third rule of logarithms that deals with exponents states that ln (M power r) = r * ln M. Using these three rules you can simplify any expression that involves logarithms to arrive at a single logarithm. The instructor shows how to apply these rules to a f...

### How To: Find the Radius of a Circle from Arc Length

The video provides two example problems for finding the radius of a circle given the arc length. Problem one finds the radius given radians, and the second problem uses degrees.

### How To: Find a missing coordinate given: coordinate & equation

In this video, the instructor shows how to find an unknown coordinate given the other coordinate of that point and the equation that passes thought the point. A point is said to lie on the graph, if the point can satisfy that equation of the line. To check if a particular point satisfies an equation, all you have to do is substitute the value of the point in that equation and check if it validates the equation. Now, substitute the given point with an unknown coordinate in that equation. If th...

### How To: Write a logarithm as a sum or difference of logarithms

This video shows the method to write a logarithm as a sum or difference of logarithms. The square root of the term given is taken out as half according to the rule. Then the numerator and denominator is divided into product of factors. This is broken into the difference of numerator and denominator according to the rule. Finally, the product of factors is expressed as the sum of factors. Now we see the domain of the term. As the term is a square root of the term it should be greater than zero...

### How To: Find the Height of a Trapezoid.

Step by step directions for finding the height of a trapezoid. Video: .

### How To: Rationalize square roots

In this tutorial, we learn how to rationalize square roots. You cannot have square roots in the denominator of an equation. You need to multiply so the square root goes away. You can do this by multiplying the top and bottom of the equation by the bottom denominator. From here, this will make the square root go away, so your equation will be normal numbers. After you have done this, you will have the equation answered and you will be able to simplify it to find the end answer. You can do this...

### How To: Express a fraction in lowest terms 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. With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to write a fraction in its lowest terms.

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

In this video the instructor shows how to find the slope of a line given two points that like on the line. Slope of a line is the measure of the steepness of the line compared to the angle made by the line with the x-axes. A line with positive slope slants forwards and a line with a negative slope slants backwards and a line parallel to x axes has zero slope. So if you are given two points (x1, y1) and (x2, y2), the slope of the line passing through those two points is equal to m = (y2 - y1)/...

### How To: Solve a system of equations with the comparison method

In this video tutorial the instructor shows how to solve equations by the comparison method. In this method he isolates either the x or y variables in both the equations and now compares the other side of equations directly to derive the value of the other variable. Now this derived value of the variable can be used by substituting it in one of the original variables to derive the value of the other variable. He goes on and shows how to do this with an example by solving it. This video gives ...

### How To: Apply the 4th Law of Exponents

This how-to video is about Fourth Law of Exponents. Before going to see this let's first know what the fourth law of exponent says. The fourth law of exponents says that "any value other than zero brought to an exponent of zero is equal to one".

### 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 surface area of a cone without slant height

Math always seems hardest until someone shows you how to do the problem and then it all seems just so simple. This video will walk you through the process of finding the surface area of a cone when you also have to derive the slant height. Use this example to help with your other cone problems.

### How To: Add consecutive odd numbers

Professor ElvisZap teaches you about adding consecutive odd numbers. You can learn this faster by drawing squares near the numbers themselves. If you are doing 2x2, draw 4 squares. They will be arranged in columns of two. For 9 you will draw 3 columns of 3. 16 are 4 columns of 4. 16 is also 1+3+5+7, which are all odd consecutive numbers. 25 are 5 columns of 5, but also 1+3+5+7+9. If you start counting 1 as the zeros odd number, then 3 as the first odd number, the nth odd number will be (2xN+1).

### How To: Find the complex conjugate of a complex number

Need a little help with your math homework? No problem, the Math Centre offers students video tutorials that will provide as a reference guide for self-study. Students get self-study resources targeted to the needs of individual courses, and teachers gain generic mathematics support and study materials for use with students.

### How To: Convert from cubic yards to cubic feet and inches

brettman6533 teaches you how to convert from cubic yards to cubic feet and inches. The volume of a cube is side cubed. If the side of a cube is 1 foot, then the volume would be 1 foot squared. Knowing that a foot equals 12 inches, you transform that into 1 times 12 in times 12 in times 12, which equals 1728 inches squared. If you want to convert a cubic yard, you have to remember 1 yard equals 3 feet. So now 1 yard squared is 1 times 3 feet times 3 feet times 3 feet, which is 27 feet squared....

### How To: Multiply nines, the easy way

See this amazing math trick to help you multiply the number nine. It so easy, you won't believe it! Who needs multiplication tables anyway?

### How To: Find the number given its percent

This video will provide you with insight into how to find a number given its percent. In the example provided, you needed to find the number which 33 is 60% of. This was achieved by simply taking the number which is a percentage of another number, in this case 33, and divide it by the percentage, in this case 60%, or 0.6. By carrying out the long division from this step, you will be able to find the original number and solve this seemingly complicated problem with ease.

### How To: Convert a fraction to a decimal

In this tutorial, we learn how to convert a fraction to a decimal. Start of by dividing the top number by the bottom number. You can do this by hand by writing out the long division of it, or you can use a calculator. If you choose to do this by hand, the bottom number will be on the outside of the division sign, and the top number will be on the inside. Once you have divided this out, the answer will be the decimal that you come up with. Continue to practice doing this will different numbers...

### How To: Find approximate area with sigma notation, For Dummies

From the people who brought you the Dummies instructional book series, brings you the same non-intimidating guides in video form. This is Mathematics for Dummies. Just watch this video tutorial to learn how to find approximate area using sigma notation, For Dummies.

### How To: Find the area of a right triangle using simple math

It is easy to find out that right triangle is only half of the square. And again there is a rectangle with a triangle shaded in red color. The red triangle is half the area of the rectangle. But to calculate just the area of triangle, we can calculate the area of the rectangle whose area is length times width. When we have a rectangle with its length and width as 4u and 2u respectively then the area of that rectangle will be equal to 8u(squared). But we already know that the triangle is half ...

### How To: Convert a decimal number into a fraction

Need to know how to convert a decimal number into a fraction in basic arithmetic? It's simple. 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). Convert a decimal number into a fraction.