Hot Math Posts

How To: Evaluate logarithms using a calculator TI-83

A video to help calculator users find the natural logarithm (log base e, or "ln") and standard logarithm (log base 10, or simply "log") of any number using a TI-83 calculator (works for any issue of the TI-83 calculator or even a TI-84 calculator). Turn on your calculator. To find the natural log of a number, press the "ln" button (the third button from the bottom left), enter the number you want to find the natural log of, press the ")" (closed parenthesis) button, then press enter. The same...

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: Find the x & y intercepts of rational functions

In this tutorial the instructor shows how to find the x and y intercepts of rational functions. Finding the intercepts of a rational function is similar to finding the intercepts of other normal equations. You can find the x intercept of the equation by setting the value of y to zero and solving the equation. Similarly you can solve the y intercept by setting the value of x to zero and solving the equation. Now while solving this rational function for intercepts if you face a situation where ...

How To: Find the opposite and absolute value of a number

View the absolute value of a number as its distance from zero. When you take the absolute value of a number, you always end up with a positive number (or zero). Whether the input was positive or negative (or zero), the output is always positive (or zero). For instance, | 3 | = 3, and | _3 | = 3 also. This property that both the positive and the negative become positive makes solving absolute-value equations a little tricky. But once you learn the "trick", they're not so bad. Let's start with ...

How To: Draw a rhombus from Geometry

In this video the author shows how to draw a rhombus when given with the values of long diagonal (D) and a short diagonal (d). Now he draws the long diagonal of size D horizontally on a sheet of paper. Now he points the mid point of the line as he explains that the diagonals of a rhombus meet at midpoints. So now he takes the ruler and draws an another line perpendicular to the first line through its marked mid point such that the length of the perpendicular line is d/2 both above and below t...

How To: Graph an inequality on a number line in Algebra

The video described here from [free math tutoring Freemathtutoring] teaches how to plot natural number on a number line in different situations. First, the author defines natural numbers, integers and real numbers. He then teaches different methods on how to plot natural numbers on a number line. The most important fact to remember is that natural numbers are greater than 0; they do not include negative numbers. Like wise, he explains different situations to plot natural numbers on a number l...

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 multi-step equations with absolute values

This educational math video describes the steps necessary to solve an equation involving absolute values. "Absolute value" refers to the magnitude of a quantity and is always expressed as a positive number. You can think of absolute value as the distance a number would be from zero if plotted on a number line. Positive 17 and negative 17 both have the same absolute value because both are 17 units from zero on a number line. Because of this, all absolute value problems have two answers, one wh...

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: Find the volume of a cylinder quickly

In this video the tutor shows how to find the volume of a cylinder. He relates the cylinder to real world examples of cans etc. Now he states the formula of the volume of the cylinder as the area of the base circle multiplied by the height of the cylinder. So the formula turns out to be V = Pi * r * r * h, where r is the radius of the base circle and h is the height of the cylinder. He solves a sample example to give you the idea of the problem. This video shows you how to find out the volume...

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!

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 the percentile formula in Statistics

In this tutorial the instructor explains the percentile formula. He says that the percentile formula is used to find the percentile rank of a data point in a group of data. He takes an example that consists of the lengths of puppies. Now he intends to find out the percentile rank of any puppy in the group. He shows that the formulate to compute a percentile rank of a particular puppy is rank R = 100 * (N< + (1/2)N= )/ Nt, where N< is the number of puppies whose length is less that the length ...

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: Apply the distributive property

The distributive property is a very important factor to consider in math and may save you a lot of trouble on your math homework. For values which lie right outside parentheses, you will need to distribute this value across the contents of whatever is inside the parentheses. You will need to multiply the value outside of the parentheses by first the first term inside the parentheses and then by the following terms inside the parentheses, distributing the value across all the terms found insid...

How To: Find the horizontal asymptotes of rational functions

Finding horizontal asymptotes is very easy! Not all rational functions have horizontal asymptotes. the function must satisfy one of two conditions dependent upon the degree (highest exponent) of the numerator and denominator. If the degree of the numerator is equal to the degree of the denominator, then the horizontal asymptote is y= the ratio of the leading coefficients. If the degree of the denominator is greater than the degree of the numerator then y= 0. If the degree of the denominator i...

How To: Write a slope-intercept equation given an X-Y table

In this tutorial the author shows how to derive a slope-intercept equation of a line given an X-Y table. He explains that the general form of slope intercept form which is y = m*x + b. Now he intends to find value of slope, i.e. m first. Now slope is change in y over change in x. He computes the slope using the X-Y values from the table. Next he substitutes a pair of x, y value in the equation to compute the value of y intercept b. Now finally substituting the values in the equation the slop-...

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: Evaluate exponents

Exponents are the times you multiply a number by itself. So 3 to the third power would equal 27. Another example could be 3 to the second would be 9. Any number with an exponent is always multiplied by the same number depending on the power. So this means that 5 to the third power would be 5x5x5, which would equal 125. One thing to remember is that when any number is multiplied by the power of 0, the number always is one.

How To: Find an angle when there are pairs of parallel lines

Consider two pairs of parallel lines, one pair horizontally and another is inclined from vertical position. If one of the four angles is given, then the other three angles can be easily identified. First select the angle which is down to the known angle, it will be same as first one. Then according to the law, that a straight lines consists of 180 degrees. For example if the known angle is 114 degrees, the unknown angle will be 180-114= 56 degrees.

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: Draw a circle with a compass for Geometry

The first thing you have to do is draw a line of the same length as the radius of the circle you want to draw. Then, open the compass the same size as the line length you draw is. Rotate the compass and you will create a circle. Please note that drawing this on a single sheet of paper can be difficult because the paper can move. Also, you can try rotating the paper, instead of the compass.

How To: Do long division

For anyone who has ever struggled with long division, this video offers some tips on how to perform this seemingly daunting task with relative ease. The example provided in this video is a very useful one and by following the steps of this video, you will be able to do long division easily. Starting from the right side of the number which is being divided, add 0's as place holders until you arrive at a number which can be divided by the number you want to divide by. Perform this one simple di...

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: 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: Solve problems related to factors, multiples, & primes

Check out this instructional math video that reviews Elementary Number Theory, which is a fancy way of saying these are problems related to factors, multiples, prime numbers and remainders. In the 12th lesson, learn how to solve SAT math problems. Here are the math problems and their page numbers that this video covers:

How To: Be a human calculator

Before we had the calculator and before we had the abacus we had the human brain to complete our math problems for us. Remember that? Well, it seems that few of us do, resorting to calculators on our phone for elementary subtraction problems and multiplication.