Active Math Posts

How To: Draw a perpendicular line from a point on a line

For people who are learning how to do basic geometry, this video will show you how to draw a perpendicular line from a point on a line using only a compass and pencil. You should first take your compass and place it on the center of the point on the line, drawing an even semicircle around the point. Then, finding the points where the semicircle intersects your original line, place the center of your compass on this point and then draw some arcs over where your point is. Repeat this on both si...

How To: Find the volume of a sphere easily

Ever wonder how much delicious chocolate pudding you could fit inside a sphere as large as the earth? Maybe not, but after watching this video, you could figure it out! Follow along with the narrator as the formula for determining the volume of sphere is explained, accompanied by helpful visual animations that make the calculations come to life. And if you can't hear the instructions, you may need to check your volume.

How To: Solve single-step equation by taking the reciprocal

In this video tutorial the instructor shows how to solve a single-step equation by taking the reciprocal. He says that in the equations of fractions containing a variable on the one side, you multiply the reciprocal of its numerical constant to it so that only the variable x stays out. Similarly we need to multiply the reciprocal value that we used on the left hand side on the right hand side too to maintain the equality. Now after simplification as only x is left on the one side we get its v...

How To: Understand Newton's second law

In this tutorial the author explains the concept of Newton's Second Law of motion which states that force is equal to mass times acceleration. So the equation to compute force F is F = m * a, where m is the mass of the body and a is the acceleration produced by the force on that body. He explains that even our weight is our mass times the gravity. So now he explains that mass of a body is constant and only our weight changes depending up on the situation we are in. If you want a clear underst...

How To: Find the surface area of a cylinder easily

In this video tutorial the author shows how to find the surface area of a cylinder. He shows a four step approach to solve this problem. First he gives us a formula to find the surface area of a cylinder, where Surface area A = 2 * Pi * R * R + 2 * Pi * R * H, where R is the radius of the base of the cylinder and H is the height of the cylinder. Now he identifies those values and substitutes them in the formula giving the surface area of the cylinder. This video shows how to compute the surfa...

How To: Use the ratio formula to find coordinates of a point

This video is recorded in a mathematics class room. It is very clear by the sound and picture. The faculty here is explaining that the ratio between two numbers can be found using various formulae and methods. For example, 3:1 is the ratio between p and q. Likewise he explained the other formulae and methods.

How To: Convert between customary units of measurement

In this video tutorial the author shows how to convert between customary units. He gives a chart which contain various convention tables showing the equivalents of various measurement units. He says a general rule that when converting a smaller unit to large unit we divide the numbers and when converting a larger unit to smaller unit we multiply the numbers. He takes a few examples and shows how to convert between various units like feet, yards, inches etc. This video shows how to convert bet...

How To: Divide fractions using the inverse

Learn to divide fractions using the inverse with this video. It is an easy way to divide the fractions just by multiplying the two fractions but reversing one of them. For example consider two fractions to be divided, (1/4) and (3/5). Then write the two fractions beside, one in the same way and another in the reverse order like remain (1/4) as it is and reverse (3/5) as (5/3). Then multiply these two terms (1/4) * (5/3) then the solution will be (5/12).

How To: Multiply and divide fractions with speed

Are you slow in multiplying and dividing your fractions? Let Mr. Rider from Speed Math 101 walk you through an easy to follow marker board math lesson that will have you managing those numerators and denominators like a pro. With a simple and easy to remember process, Mr. Rider walks you through common examples, misunderstandings, and problems. Improve your speed and accuracy in math class with the Speed Math 101 method. Avoid the usual pitfalls of improper fraction reduction that might you l...

How To: Understand the basics of velocity & acceleration

The video Understand The Basics of Velocity & Acceleration (301974) is a tutorial into the physics of position, velocity and acceleration. Each concepts are explained in terms of physical properties for the purpose of mathematical equations. Acceleration for instance is the increase in speed of an object in time. It is important to understand how these words are defined then translated into mathematical quantities in order to do problems in physics. With the correct understanding of forces an...

How To: Shade a system of inequalities

In this video the instructor shows how to shade a system of inequalities. He says that shading a system of inequalities is similar to shading a single inequality but in the former case you tend to shade more than one inequality in the same graph. He shows how to do that using an example set of inequalities and plots the lines on the graph. He uses dotted lines for lesser than or greater than inequalities and uses straight lines for inequalities which contains the equal to symbol. Now he shade...

How To: Add and subtract to solve equations

In this video the tutor shows how to add/subtract to solve equations. He says that when we are trying to solve simple equations we need to perform the same operation on both the sides of the equation i.e. if we are adding something on one side of the equation we need to add the same thing on the other side of the equation too. Similarly for the subtraction too. He says that by doing this we still maintain the equality of the equation. He shows how to do this with an example. This video gives ...

How To: Identify arithmetic sequences and find the nth term

This is a one of the coolest videos about arithmetic sequence, it has a very clear explanation about the arithmetic sequence formula and also more than one example which would help the viewer to learn this formula and its implementation in a easier way. This video is a also very helpful for the people who appear for interview since it is a very basic formula that every science student must remember.

How To: Understand conservative vector fields

A conservative vector field is defined as being the gradient of a function, or as a scaler potential. Conservative vector fields are not dependent on the path; they are path independent. Conversely, the path independence of the vector field is measured by how conservative it is. These fields are also characterized as being ir-rotational, which means they have vanishing curls. Actually, ir-rotational vector fields are conservative as long as a certain condition on the geometry of the domain is...

How To: Divide fractions and then reduce them

In this tutorial the instructor explains how to divide fractions. He gives a three step approach where in the first step we take the reciprocal of the second fraction. In the second step the newly arrived at fraction is multiplied with the original fraction. Now finally in step three the result is deduced and the answer is obtained. This video explains clearly and simply a three step procedure of how to divide fraction.

How To: Divide fractions by "flipping & dipping"

The instructor in this video gives a tutorial on how to divide fractions by "flipping & dipping" method. He says that to divide two fractions we need to follow two steps of flipping and dipping. He says to write the first fraction as it self and flip the second fraction and write it beside. Now he says that instead of dividing we are dipping and multiplying both the fractions which results in the division of the original fractions. Now after multiplying the fractions we get a fraction which c...

How To: Draw a dotted/solid line when graphing an inequality

In this video the tutor shows when to use a dotted line and when to use a solid line while graphing lines in coordinate geometry. He says that we should use a dotted line to plot an inequality which contains the symbols less than or greater than. He also says that we should use a straight line when plotting an inequality which contains the signs less than or equal to and greater than or equal to. He goes on and demonstrates this idea with some examples. This video shows how to use different l...

How To: Find the slope's unit of measure

This educational video from free math tutoring shows how to calculate the slope of a line and assign units to the answer obtained. This video assumes that the viewer is familiar with the concepts of axes and co-ordinate geometry. The narrator uses a commonly used formula to calculate the slope of the line in the first section of the video. In the second section, the narrator demonstrates how to assign units to the answer, as per the question asked.

How To: Understand positive, negative, zero & undefined slopes

This video explains how to find the sign of slope of a line. The way shown means that you can find whether it is positive or negative without knowing its equation. It uses a simple analogy so that anyone would be able to use this method, even without much math knowledge. Being able to find the slope of a line is very important, as it leads to advanced function and calculus.

How To: Find the interior angle sum of a polygon

In this tutorial the instructor shows a method to compute the interior angle sum of a polygon. He gives us the formula for the interior angle sum of a convex polygon as (n-2) * 180 where n is the number of sides of the polygon. He goes and take a 6 sided polygon as an example and does the math by substituting the value of 'n' in the equation and arrives at the result. This video clearly gives the formula and demonstrates with an example of how to calculate the sum of interior angles of a poly...

How To: Calculate the area of irregular shapes

In this tutorial the instructor shows how to compute the area of irregular shapes. He demonstrates this with an example showing an irregular area and says that as there is no direct formula to calculate it, you need to break up the irregular area into identifiable simple geometric figures. He goes on and breaks the irregular shape into a square, a triangle and a trapezoid. Now he computes the individual areas using a standard formula and sums them up to arrive at the final complete area of th...

How To: Use the Fundamental Rule of Proportions in Algebra

The author in this video explains the concept of fundamental rule of proportions. Fundamental rule of proportions means cross multiply. He explains that to arrive from an equation which has fractions into the one without equation multiply the top of left side with the bottom of right side and equal it with bottom of left side multiplied with top of the right side. In this way proportions can be cross multiplied to arrive at an algebraic expression. If you want to master the rule of proportion...

How To: Do a similarity transformation in Geometry

In this video the author shows how to do similarity transformations. He says that similarity transformations are used to draw the similar images at a different location and the k value is most important while doing this kind of transformation. He says that a negative k value tells that the copy of the shape will end at the opposite side of the origin to the original shape. He says that a positive k value tells that the copy will lie on the same side of the origin. Next thing about the k value...

How To: Multiply algebraic fractions

This video offers some insight into a few more difficult concepts of mathematics by teaching you how to multiply algebraic fractions. Given polynomials in fraction form, you should first try to factor all your polynomials into their simplest form in the hopes that some factors will be able to cancel each other out. After performing these steps, you can then combine your factored polynomials together in order to get your final product. The various examples provided in this video will offer goo...

How To: Draw a translation in Geometry

In this tutorial, the instructor shows how to do a translation in geometry. Now he shows this by using various drawings and by practically explaining it while performing the translation. He first shows how to set up the translation line and now goes on to translate each and every vertex by drawing a parallel line to the translation line through each vertex, which is the same length as the length of the translation line. Now he combines the end points of the translated lines which gives us the...

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: Add fractions with like and unlike denominators

This video shows a tutorial of adding fractions. The first example shows a fraction that has like denominators so all you had to do is add the denominators. In the second example it shows two fractions that do not have like denominators. Therefore, you need to find the greatest common factor among the two denominators. Once this is found, you multiply the fraction on both the numerator and denominator to make both of the fractions match. Then all that is left is to add the numerators to finis...

How To: Determine if a point lies on a line in slope intercept

In this video the author shows how to find out if a Point lies on a Line in Slope Intercept Form. He shows it by an example where he takes a point, which is an ordered pair in the form (x, y) and a line, which is an first degree equation. Now he substitutes the values of x and y in the equation and checks if both the sides of the equation match. If it matches we can conclude that the point lies on the line. By following the method given in this tutorial you can find out if a given point lies ...

How To: Calculate and solve for density

Density is a means of representing how much mass is contained in the body of an object. The basic formula is: Density (D) = Mass (M) / Volume (V) so D=M/V. Density is important to know for buoyancy and to understand how heavy an object is. This video will show you three examples of measuring density so you can learn and put it to good use.

How To: Multiply decimals together

This video is about multiplying decimals together. The numbers to be multiplied are 1.003 times 2.8. First, you multiply like you would normally. Apply the number of decimal places. Count total number of digits to the right of the decimals. In this case it four. Apply the number of decimal places to the result. Starting from the right move four decimal places. Put the decimal point after the "2".

How To: Find the areas of a parallelogram and a triangle

The video teaches the viewer how to find the area of a parallelogram and the area of a triangle. For a parallelogram, the first step is to find the right angle, the line perpendicular to the base (this is a line you draw, not part of the parallelogram). The height of the line that forms this right angle with the base is the perpendicular height. Next, find the length of the base. The area is the base times the height. For a triangle, find the right angle with the base (again a line you draw)....

How To: Add decimals

This video explains how to easy add decimals. Adding decimals can seem to be a tedious job, and a single mistake can result in a completely different number. In reality, it is quite easy, and with a good method and some practice it can be done quickly. Write the two sets of numbers out, lining them up in columns. Keep the decimal points on top of each other and line up the non-decimals with non-decimals and the decimals with decimals. Start at the right-most column and add it up. If it become...

How To: Divide variables

This is a helpful video provided by Math Problem Generator. It deals with the complex challenges of dividing variables. The audio is great and provides specific examples of dealing with multiple types of this problem. The video lays out three simple steps. The first being to simplify the coefficient, the second being to divide the variable, and the third being to deal with the results of the division. The information is clearly presented and best of all it's free. I think we all wish there we...

How To: Find the area of a triangle in geometry

This is a tutorial on how to find the area of a triangle. To show the viewer how it is done, the video walks us through a simple example step by step. The first step is to find the base and the height (in this example 5 and 6). The next step is to multiply them together (making 30). Next, the answer is divided by two (to get 15). Finally, the units are written next to the answer (in this case inches squared). This is beneficial as it is a very easy and user friendly way of learning how to fin...