# Hot Math Posts

### How To: Do algebraic long division

In this video, you can learn how to do algebraic long division. Take an easy example, such as 88 divided by 4. You are actually dividing 4 into 88. You take the 4 and divide it into the 80, and your answer is 20. Multiply (20 x 4) and you get 80, then subtract the 80 from 88 and you get 8. You then divide 4 into the remaining 8 and your answer is 2, giving you a final answer of 22. Try a harder problem, such as 2105 divided by 12. You are dividing 12 into 2105. The easiest way to handle this ...

### How To: Simplify a quadratic formula result

In this video the tutor shows how to simplify a quadratic formula result. You can solve a quadratic equation using the quadratic formula. The first thing you have to do when given the quadratic equation is bring all the terms to one side so that you have a zero on the other side of the equals to sign. Now the formula to calculate the roots of the quadratic equation ax*x + bx + c = 0 is x = (-b + root of(b*b - 4*a*c) ) / 2 * a. The other root can be obtained by using the minus sign before the ...

### How To: Graph the greatest Integer or floor function

The video shows the explanation of greatest integer function. This video explains this with the help of graphs. The video first describes the basic greatest integer function. This means the greatest integer less than or equal to the number gave. The graph of this function is drawn. The video then shows the variations of this function. The first variation shows the function that replaces the 'x' coordinate with it subtracted by three. This shifts the graph to the right by three units. The seco...

### 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: Complete Fahrenheit to Celsius conversion

This video shows you how to convert temperatures from Fahrenheit(F) to Celsius(C). In the video, the example of 75 degrees F is used. The formula for converting Fahrenheit to Celsius is given by temperature in Celsius= (temperature in Fahrenheit- 32)/1.8. So for 75 degrees F we take 75 in place of temperature in Fahrenheit. Therefore the equation becomes (75-32)/1.8=C . Further 43/1.8=c and finally C= 24. Hence 75 degrees Fahrenheit= 24 degrees Celsius . This conversion is used as Celsius is ...

### How To: Find the equation of a tangent line

This is the video about how to find the equation of a tangent line. As you may recall, a line which is tangent to a curve at a point a, must have the same slope as the curve. Therefore, the slope of the tangent is m = lim f(a + h) - f(a) h-->0 h Since the slope equation of the tangent line is exactly the same as the derivative definition, an easier way to find the tangent line is to differentiate using the rules on the function f. For example, Find the slope of a line tangent to the function ...

### How To: Draw a right trapezoid in Geometry

Watch this video to learn how to draw a right trapezoid using given specifications for lengths of sides. A right trapezoid is a four-sided shape with two right angles and two parallel sides. First, draw the long base. Then draw a 90 degree angle at one end of the base, using a protractor. Mark the angle to show it is 90 degrees. Then draw another 90 degree angle at the top. This is the first video in a set--to finish learning you must watch the next segment. If you watch these videos you will...

### How To: Solve an equation by the distributive property

In this simple tutorial the tutor shows how to solve equation by the distributive property. He states that when there is a number which is multiplied to a full equation, we have to multiply each and every term of that equation by that multiplying number. This is called the distributive property as the value is distributed to each and every term inside the equation. He goes on and solves a problem based on this property to give a clear idea of the property. This video shows how to solve equati...

### Use the quadratic equation: finding the mirror point

In this video the tutor shows how to find the mirror point using a quadratic equation. He says that to graph a parabola you need to find the mirror point symmetrical to the Y-intercept. Now he explains how to find a mirror point using an example with sample values. He begins with saying that the Y-coordinate of the mirror point is same as the Y-coordinate of the Y-intercept. Now you have to find the x coordinate of the mirror point which he shows that it is double the x-coordinate of the vert...

### How To: Find the area of a ring w/ the areas of 2 circles

Doina Popovici's video explains how to calculate the area of a ring. She takes us really slow, down to all the steps of this process. It's very important that she explains every math formula and operation so you cannot get lost into this solving. The video uses nice pictures and colors in order to make learning easier and nicer for those who are interested. At the end of the video you'll surely be able to solve by yourself a problem like that and your appetite for geometry will grow significa...

### 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: Add positive & negative numbers

This explanation of positive and negative signs in addition is beneficial and easy to understand for young school aged children. The tutor of this video explains briefly about what to do with the different signs on both side of addition problem. The number line helps the viewer of this video to visually understand the concepts discussed. The tutor explains the direction of number line evaluation is dependent on the left side operand, which is also used to understand the concept of a number line.

### How To: Calculate percentages

Learn how to calculate percentages with this easy video tutorial! One of the easiest way to calculate percentages is as follows:

### How To: Calculate simple interest

Learn how to calculate simple interest with step-by-step instructions using the formula I=prt. Simply defined, interest equals principle times rate times time. The video shows various examples of calculating this formula by plugging different variables into the equation. Although, these calculations can seem hard to follow, the way they are presented is straightforward and simple to understand. The video also explains converting percentages to decimals, which is the cornerstone of applying th...

### 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: Find a missing part of a triangle, similar to another

In this tutorial the author shows how to find out the missing part of a triangle that is similar to another triangle. He explains the concept of similar triangle diagrammatically by showing that similar triangles have similar angles and parallel sides. Now he labels sides of similar triangles and marks the value of unknown side as variable x. Now in similar triangles as the lengths of sides of proportionate he shows how to write a equation of proportion and solves it finding the missing part ...

### 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: 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: Find the perimeter & area of a complex figure

In this video tutorial the author shows how to find the perimeter and area of a complex figure. He shows that a complex figure can be subdivided into standard geometric figures. In the current example he divides the complex figure into a rectangle and a triangle. Now he computes the perimeter by adding the three sides of the rectangle and the two sides of the triangle. Similarly he computes the individual areas of the rectangle and the triangle and finally adds then up to find the area of the...

### How To: Find a slope of a line parallel/perpendicular to it

This video tells you how to find a slope of a parallel / perpendicular to it. In the equation y = mx + c, m is the slope. To calculate the slope of a line that is parallel to another line, you have to consider the rule m1 = m2 which means slope of the first line m1 is equal to the second line m2, if both the lines are parallel. Take the equation y = 2/3x - 7.2/3 is the slope. According to the rule m1 = 2/3 and so m2 = 2/3.Now to calculate the slope of perpendicular line you have another rule ...

### How To: Find the volume of a cylinder

This is an excellent educational video on mathematics. This video teaches you how to find the volume of cylinder with an example. The volume of cylinder is the bottom area multiplied by the height. Here, the height is 12 inches and the radius is 9 inches. The bottom area is Pi r square=piix81 sq inches. volume = piix81x12 = piix972

### 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: Learn Calculus in 20 minutes

Did you sleep all semester in your Calculus class? Are you just waking up now to realize you have a test on Monday and that you're totally screwed? Well, luckily you can learn an entire semester worth of Calculus in just twenty minutes... or at leasts that's the hope.

### How To: Solve percentage problems

Check out this instructional math lesson that demonstrates how to solve percentage problems. In the 13th lesson, learn how to solve SAT problems using the Official SAT Study Guide. Here are the math problems and their page numbers that this video covers:

### How To: Add Mixed Numbers Tutorial

This step by step video teaches how to add mixed numbers AKA mixed fractions easily!

### How To: Convert a Mixed Number to an Improper Fraction Tutorial

This easy tutorial will show you how to convert a mised number into an improper fraction in a few easy steps.

### How To: Divide Fractions Tutorial

An easy step by step video tutorial on dividing fractions.

### How To: Multiply Fractions Easy Tutorial

In this step by step video I'll show you how to multiply fractions.

### How To: Subtract Fractions with Unlike Denominators Step by Step

Learn how to subtract fractions with unlike denominators by watching this easy video tutorial.

### How To: Subtract Fractions with Like Denominators

This easy video tutorial teaches how to subtract fractions with like denominators step by step.

### How To: Add Fractions with Unlike Denominators Tutorial

This video tutorial teaches you step by step how to add fractions with unlike denominators.

### How To: Add Fractions Tutorial

Learn how to add fractions with this easy step by step video.

### How To: Solve Word Problems Involving Volume of a Pyramid

Learn how to solve geometry word problems. For example, how would you solve the following problem?

### How To: Use a Venn Diagram to Solve Probability Problems

Video covering how to set up a Venn diagram. The video covers how to draw the diagram and then look at a set of data and place the data in the correct part of the Venn diagram. The sample problem is as follows.

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

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

### How To: Find the Area and Volume of a Hemisphere

A hemisphere is sphere that has been cut in half. When you cut the sphere in half you are left with the great circle, plus half of a sphere. This fact can be used to find the area, and the volume of a hemisphere. The video works several example problems in which the area and volume of a hemisphere is calculated.

### How To: Multiply by 11 Faster Than a Calculator

Yes, with this simple technique you can multiply 2 digit numbers in your head. The video also reviews a really easy method for multiplying larger numbers by 11 in a simple fashion.

### How To: Multiply Any Number by 11 Easily

This video shows two techniques for multiplying any number by 11. Using these techniques you will find it is easier than using a calculator.

### 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 the Surface Area of a Cylinder.

Step by step directions for finding the surface area of a cylinder. In order to calculate the surface area of the cylinder you find the area of the two bases and add this to the lateral area.