Hot Math Posts
How To: Get a fraction from a recurring decimal
In order to pass that big Algebra test you will need to know how to get a fraction from a number with a recurring decimal. If you are looking for a shortcut, look no further than this tutorial.
How To: Find surface area and volume of a sphere
In this how to video, you will learn how to find the volume of a sphere and surface area. Let's say you need to find the volume of a sphere with a surface area of 200 cm cubed. You will need to know the formulas for surface area and volume of a sphere. The formula for surface area is 4 pi r squared. The formula for volume is 4/3 pi r cubed. Plug in the surface area of 200 cm cubed and plug it into the formula. You should get an answer of about 3.99 cm. Now you just have to solve for the radiu...
How To: Find the length of a segment using the midpoint II
First of all in the given question you have to write down the values of the total length of the line segment, PS=15. The length of the line segment, QR =3. Now you have to find the value of line segment RS. Because you know that the Q is the midpoint of the line segments PQ and QS must be equal. Therefore you can find out the length of the half of the segment using the midpoint. Subtract the value of QR from QS. Given that segment PS=15 and Q is the midpoint, you can conclude segment PQ=7.5 a...
How To: Figure out the area of quadrilaterals
Quadrilaterals are four sided shapes that are closed. They are polygons. Quadrilaterals can be classified broadly in two ways. If the quadrilateral has a two pair of parallel sides then it falls in to the parallelogram category. Further now it can be broken down in to other shapes like square, rectangle, rhombus. If it has only one pair of parallel side then it falls into the trapezoid category. To compute the are of a trapezoid first you need to know the lengths of the parallel sides. Add th...
How To: Do long multiplication
In this video the instructor gives you sample as of how to SLEP long multiplication. You start by breaking the numbers up to simpler forms. If you have a two digit number that your multiplying by a another two digit number you multiply the first two digit number and then buy the second digit of the second two digit number. You have to remember to carry the remainders. You then add your two multiplicative lines together giving you the sum. this can be done to cover any set of multi-digit numbe...
How To: Calculate the circumference of a circle
This video shows how to calculate the circumference of a given circle. The video first describes the circumference or perimeter of a circle as the distance around the outside of a circle. To find the circumference we need either the radius or the diameter of the circle. When you know the diameter of the circle, the formula to find the circumference denoted by 'C' is 'pi' times the diameter, where 'd' is the diameter and 'pi' is a constant, the approximate value being 3.14. And when you are gi...
How To: Graph linear equations using y=mx+b
This video is an instructional guide about Graph Linear Equations presented in algebraic form. It is an easy to follow, step by step guide to solving such equations using the graph intercept formula. The first example equation is Y = 2x -1 over y = mx + b. The video then shows you how to breakdown the equation into manageable sums using fractions to represent the data, and then presents the formula for interpreting the answer from these sums onto the graph co-ordinates. The second and third e...
How To: Find a percentage of a number
This video in the Education category will show you how to find a percentage of a number. For example, what is 12% of 56? The simple way to do this is to find 10% of 56; which is 5. 6. Then you find 1% of 56 is .56. Then you add 10% plus 1% plus 1%, that is, 5. 6 plus .56 plus .56; which is 6. 72. And that’s the answer. The other way to do this is to make decimal out of 12; which is .12. Now multiply .12 by 56 and the product is 6. 72. These are the two methods of finding out a percentage of a...
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: Understand the Pythagorean Theorem
In this video Ken teaches you about the Pythagorean Theorem. The Pythagorean Theorem is used to find the missing length of a side of a right triangle. By watching this video, you will learn how to find any the length of any side by using a simple mathematical formula. Ken walks you through various examples changing the dimensions of the triangle you are solving as well as changing the side you are solving. Ken even includes a real world application to further your understanding of the Pythago...
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: Find the area of a parallelogram using geometry
The video shows us how to find the area of parallelogram using geometry. Here in this video it is done by using an example where the parallelogram is given ABCD. The area of the parallelogram is base times height (bh). Here the base is given as 15 but the height is not known but it is represented by the segment BD. To find the value of h, let’s use right triangle BDC on the right side of the figure. Since base is 15 and the opposite side of the parallelogram is congruent, the hypotenuse of th...
How To: Simplify radical expressions
In this video the instructor shows who to simplify radicals. If you have a term inside a square root the first thing you need to do is try to factorize it. First factorize the numerical term. Write down the numerical terms as a product of any perfect squares. Now split the original radical expression in the form of individual terms of different variables. Now you can pull out the perfect square numerical factors out of the radical. Similarly for the variable terms write the variables as power...
How To: Find the circumference of a circle quickly
In this instance we are going to Find the circumference of a circle by applying formula C=2pr where 'C' is circumference of a circle, approximate value of 'p' is 3.14 because it is irrational number and 'r' stands for radius i.e. half of diameter. So by applying this formula we can easily calculate circumference of a circle if radius is given or we can also calculate radius if circumference of a circle is given. One thing to remember is that unit we use for circumference of a circle is cm, in...
How To: Find the area of a rectangle using geometry
This video shows how to compute the area of a rectangle given the length of one of its sides and its diagonal. First start by drawing the picture of the rectangle. Now draw the diagonal and label the known lengths. In the diagram, the diagonal and two sides of the rectangle form a right-angled triangle. The breadth of the rectangle can be computed using the Pythagorean theorem. Finally, compute the area of the rectangle by multiplying its length to its breadth.
How To: Factor the difference of squares
In this video the instructor shows how to factor the difference of squares using a formula. The formula to find the difference of squares can only be applied if you have two perfect squares. The formula is (a * a - b * b) = (a - b) * (a + b). That is the difference of squares of two numbers is the product of sum of two numbers and difference of two numbers. So when you need to find the difference of squares of two numbers substitute the values in the above formula to directly solve for the fa...
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: Factor and collect like terms
In this video, the instructor shows how to collect like terms and factorize. When you are given a linear equation, the first thing you do is to try to organize it. Pair up the like terms. Add the numerical coefficients of terms with the same variables. This is called collecting the like terms. In case you see any common factor across all the terms, pull it out and tag it to the parenthesis. In this way, you can factorize the equation. Next, bunch together your like terms and sum them up. The ...
How To: Convert temperature using y = mx + b
In this video the instructor shows how to do temperature conversions using y = m*x + b. Now if Celsius is represented by the variable C and Fahrenheit is represented by the symbol F, you can replace then in the previous equation in place of the variables x and y giving you the equation C = m*F + b. Now to solve for the values of the constants m and b you need to have values of two sample temperatures in both Celsius and Fahrenheit. Take the first sample and substitute in the above equation gi...
How To: Solve percent equations
In this tutorial the instructor shows how to solve percent equations. The general form of a percent equations is that a is b% of c. As there can be three kinds of variables a, b, c, the questions involving percent equations can be of three types having one of the three variables unknown. These kind of percent statements can be solved easily by setting up an equation. So, to convert percent statement into a equation replace the unknown term with n, the 'is' term with equals sign and the '%' si...
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: 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: 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...
How To: Simplify a complex fraction w/ binomial denominators
To simplify a complex fraction, turn it into one fraction on the top divided into a fraction on the bottom. Once this is complete, you will turn the division into the two into a multiple by the reciprocal, factor, and then cancel. To make a division, find the lowest common denominator of both the top and the bottom. Once you get this division equation, look carefully at the equations. If something can be easily canceled, go ahead and cancel it out at this time. If you cannot cancel anything a...
How To: Determine the area of a trapezoid
Need to figure out the area of a trapezoid for a household project? Even if you just want to sound smart, there is a simple formula that can be used every time you need to find the area of a trapezoid. Try the formula and see how good you are at geometry.
How To: Shift a graph
This video will demonstrate exactly how to shift a graph on a x,y axis. When shifting a graph on the x axis you will need to replace x with x-h; where h is the variable to shift the graph. No matter how far you need to shift a graph, h is always the number of units you are shifting; shifting up or right is represented as a positive and down or left is negative. Just plug in your units into your equation and you will have your shifted graph.
How To: Simplify square roots
This is a video tutorial on how to simplify square roots. To simplify square roots, one must have the knowledge of splitting numbers into prime factors. For example,12 can be split into 4*3 and further more into 2*2*3. Here we see that all the factors are prime numbers. So the square root of 12 can be written as 2*square root of 3(as shown in the video). The method used in the video is applicable for simplifying any square roots as any number can be split into prime factors. Follow the video ...
How To: Find the equation of an ellipse given a graph
Notes College Algebra teaches you how to find the equation of an ellipse given a graph. You first want to find out the center of the ellipse, which in the video is (2, -3). The major axis is parallel to the X axis. The equation is (x - h) squared/a squared plus (y - k) squared/a squared equals 1. A is the distance from the center to either of the vertices, which is 5 over here. B is the distance from the center to the top or bottom of the ellipse, which is 3. You then use these values to find...
How To: Divide integers quickly and easily
This tutorial explains how you can divide integers. Dividing integers is similar to multiplying integers. A positive divided by a positive gives you a negative number. A negative divided by a negative gives you a positive number. And a positive divided by a negative, or a negative divided by a positive, will results in a number. Some examples: -15 divided by 3. In this problem we're dealing with a negative divided by a positive. So, the answer will be negative. The answer is -5. Another examp...
How To: Simplify algebraic equations w/ the minus-one trick
Just follow a few steps to simplify algebra with the minus one trick. First step is to take two algebraic equations with having numerator and denominator algebraic equations. Second step is to divide the denominator with numerator. For example, it have like -c/c, it gives like answer as -1, but we have another type like (c-a)/(a-c) - to solve these types of steps, like multiply numerator with minus(-), it gives the common the minus and -(a-c)/(a-c), then it gives -1 as a answer.
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: Find the area of a hexagon
In this video you can learn how to find the area of a hexagon. Visualize that the hexagon is made up of six equilateral triangles, with each side of the hexagon as the base for a different triangle. Determine the length of any triangle side by measuring it. Each side should be equal in length to any other side. L will represent this number. Determine the height of any triangle. This can be done by putting one end of your ruler at the halfway point on any side of any triangle and the other end...
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: Find the area & perimeter of triangles & squares
When you are figuring the area of a square, you only need to know the height and width of the shape. Once you know the height and width, multiply them to get the area of the square. To find the perimeter of the square, add all four sides together. To find the area of a triangle, multiply together two of the sides (not the hypotenuse) and then multiply that figure by 1/2. To find the perimeter of the triangle, add all three sides together.
How To: Find X-bar with the Z-score formula
In this video tutorial it shows you how to find the x-bar by using the Z-score formula. In the beginning of this video the formula is displayed on the right, while the values that you need to plug in are on the left. Once you plug in the values and do the cross multiplying, all you have to do is get x-bar by itself on one side of the equation. This is a simple problem on using the z-score formula to find x-bar, it can help you solve more complex problems in the future.
How To: Understand the Rule of Corresponding Angles
This video explains about the rule of corresponding angles. When measuring the angle between the parallel lines (i.e.) Line1 and Line2 across the straight line. The angle A and angle B are equal. The angle C and angle D are equal. The angle E and angle F are equal. Finally angle G is equal to angle F. So, the angle between the parallel lines in all the angles are equal. Hence, this is the rule of corresponding angles. This video is very useful to basic high school geometry courses. Correspond...
How To: Understand basic probability with examples
This is a very basic overview of probability, possibly intended for an eleven year old. It is a very good introduction to probability for one that has never encountered probability before. The instructor is not always clear in his intentions. Someone watching this video would learn about probability, ratios, percentages, and fraction. There is a set of required knowledge to understand what the instructor is talking about. The instructor uses very nice diagrams and also gives nice explanations...
How To: Find the perimeter of a parallelogram
One thing that you will need to know in order to pass Geometry is how to find the perimeter of a parallelogram. Parallelograms are quadrilaterals with two pairs of parallel sides. It is not difficult to find their perimeter, but you will need to know a few steps. Check out this video for tips on how to do this in your math class and ace that big test.
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 units of measurement
This video shows you how to easily convert units. The first step you have to do is setup a proportion between a known conversion (e.g.. convert 2.5 km to m: 1km = 1000 m, => 1 km/1000 m = 2.5 km/X m). The second step you have to do is solve the equation by taking the cross product and find out the missing value (x). (e.g.. 1 km/1000 m = 2.5 km/X m <=> 1 x X = 1000 x 2.5 <=> x=2500 m). That's it! Good Luck!