Active Math Posts
How To: Find the standard deviation with the Z-Score formula
In this tutorial, we learn how to find the standard deviation with the Z-Score formula. First, take your problem and write it out one by one underneath each other. Then, you will need to substitute the numbers in for the variables that are in the problem. Once you do this, you will follow the basic rules of math to find out what the answer to the problem is appropriately. Once you have done this, finish off the problem to find the answer, then you will have found the standard deviation using ...
How To: Evaluate functions
In this tutorial, we learn how to evaluate functions. A function is an equation with an input and an output. For the value of "X" there is going to be a value for the rest of the values that are in the equation. To start, write out the equation, then substitute the "x" with the appropriate number. After this, substitute the "x" in the rest of the equation where it belongs. Once finished, work out the rest of the equation in the appropriate order. Now you will be able to finish it and get the ...
How To: Draw an isosceles trapezoid
This is a video tutorial in the Education category where you are going to learn how to draw an isosceles trapezoid. This video demonstrates how to draw an isosceles trapezoid with a long base (B), a short base (b) and a 35 degree angle. First you draw the long base. Now center the short base at the center point of the long base and mark the end points of the short base with dots. Next draw perpendicular dotted lines from the dots extending upwards. Draw 35 degree angles from either end of the...
How To: Use the PRIME operator in math
In this video, we learn how to use the PRIME operator in math. The prime operator is the opposite of something in the equation. Take a look at the illustration in the video that is shown. Once you see that, you will be able to tell what A prime and B prime are. A prime is the opposite of "A". If a number is shaded in "A" it should not be shaded in "A Prime". The same goes for the prime of the letter "B". Just pay attention to what the numbers selected for each letter is, then use the opposite...
How To: Find the interior & exterior angles of a triangle
In this tutorial, we learn how to find the interior and exterior angles of a triangle. I triangle has three angles and their measurement when added together will equal 180. For example, if one angle is 80 and another is 30, then start off saying the equation equals 180. Write in 80+30+X in front of the equals sign, then subtract the combined like terms from the 180. After this, you will have found the value of x, which will also be the measurement of the last angle. Make sure to write out the...
How To: Understand fractional exponents
In this tutorial, we learn how to understand fractional exponents. Starting with an example, let's say you have the square root of four as an equation. The answer to this is two. A fractional exponent is not much different than this problem. Let's say you have 4 to the 1/2 power. This would be equal to (2 squared) 1/2. Now, using the third exponent law, the term becomes 2 to the power of two x 1/2. This will leave you with the answer of two. Now you know how to get the correct answer and can ...
How To: Draw a parallelogram given base, angle & altitude
In this tutorial, we learn how to draw a parallelogram given base, angle & altitude. First, you will draw the base of the parallelogram, using your ruler to measure out the line. Next, you will draw a dotted line perpendicular to the line that you just drew that is 3 cm in length. Then, you will draw another dotted line on top of the one you just drew. This dotted line shows where the top of your parallelogram will be. Then take your protractor and draw it at the angle the problem gives you. ...
How To: Do fraction multiplication
This is a video tutorial in the Education category where you are going to learn how to do fraction multiplication. Before multiplying two fractions together by multiplying across the numerators and the denominators, you should always try to cross cancel as your 1st step. For example in the problem, (-15/4) x (14/5), 15 and 5 will cross cancel to 3 and 1. Similarly, 14 and 4 will cross cancel to 7 and 2. So, what you will get now is (- 3/2) x 7. Also you should take care of the signs. In this ...
How To: Apply the 6th Law of Exponents
This is a video tutorial in the Education category where you are going to learn how to apply the 6th Law of Exponents. The 6th law of exponents says, to raise a product to a power, you can multiply each of its factors by the same power. For example if you have (acm) to the power x, that will be equal to the product of (a to the power x), (c to the power x) and (m to the power x). How is this done? (acm) to the power x is same as (a to the 1, c to the 1 and m to the 1). What we are doing is, w...
How To: Compare 2 distributions with the Z-Score formula
This is a video tutorial in the Education category where you are going to learn how to compare 2 distributions with the Z-Score formula. In this example Doug's class has X bar as 71 and a standard deviation of 4. Corey's class has X bar as 68 and a standard deviation of 11. If both Doug and Corey beat the class average and have the same standard score, will Doug have a lower grade than Corey? If both of them have a standard score of 1.5, then Doug will get 77 marks and Corey will get 84.5 mar...
How To: Multiply fractions easily
In this tutorial, we learn how to multiply fractions easily. First, you will need to know where the numerator and denominator are in the equation. Numerator is on top and Denominator is on the bottom. When you multiply fractions, you multiply the top and then the bottom of the fractions straight across. Once you have multiplied them, you will write your number out as a fraction. Make sure you reduce your fraction as much as you can, or else it will not be a correct answer. To reduce it, see w...
Find the discriminant (DELTA): quadratic equation
The discriminate of any equation in any degree plays an important role in determining the roots of that equation.
How To: Understand the properties of a square in Geometry
In this tutorial, we learn how to understand the properties of a square in Geometry. The four angles on the inside of a square have to be right angles. All but be 90 degrees and add up to 360. A square has four equal sides, which you can notate with lines on the sides. The diagonals of the square cross each other at right angles, so all four angles are also 360 degrees. Diagonals have to be equal in length to each other as well. Once you better understand this, you will be able to learn more ...
How To: Find the percent of a number
In this tutorial, we learn how to find the percent of a number. First, take the percent and convert it into a decimal. Then, multiply this by your other number. After this, you will come up with the answer to the problem. An example of this would be if you had the question: what number is 25% of 40. First, you would find the decimal of 25, which is .25. After this, you would multiply that by 40 and then come up with the correct answer, which is 10. Repeat this process for the different equati...
How To: Find abc, curve direction & y-intercept (quadratic eq)
In this tutorial, we learn how to find abc, curve direction & y-intercept (quadratic eq). First, you need to find the a,b, and c of the equation. A will equal what the coefficient is in the equation, B will equal the second, and C will equal the third term. This tells us if the numbers are positive or negative, so so know if the parabola opens up or down. To graph C, you will know what the y-intercept is going to be, then find the matching units. After this, you will use B to shape the parabo...
How To: Use the Quintile Formula in Statistics
In this tutorial, we learn how to use the Quintile Formula in Statistics. To find the quintile rank of a formula that is in a certain set, you will first need to count the number you are given. Then, read the equation so you understand what the R, N, equal side, and other numbers mean. Once you understand what all of these mean, fill in the formula with the correct information. Use the information you are given in the question to fill it into the equation. When finished, you will apply the ru...
How To: Simplify algebraic fractions
In this tutorial, we learn how to simplify algebraic fractions. First you will need to simplify the fractions. You need to factor the numerator out, figure out what A is and what B is. Then, figure out what C is and what the products equal as well. When you have these, you will be able to fill these factorizations into the equation. Rewrite the equation with your figured out numbers inside, then you will be able to solve the equation. Use the rules of PEMDAS to figure out how to solve it, the...
How To: Solve word problems in Algebra
Having trouble with word problems in algebra? Watch this video to clear a few concepts as well as to learn how to systematically tackle word problems in exams.
How To: Write a slope intercept equation for a line on a graph
A topic which is taught during school days: The slope - intercept equation of a line in a 2 dimensional space.
How To: Divide fractions step by step
In this tutorial, we learn how to divide fractions step by step. First, you will need to know the different parts of the fraction, the numerator and the denominator. After you know these, you will flip the second fraction in the equation so the numerator is at the bottom and the denominator is at the top. Once you do this, change the division sign to a multiplication sign. Now, you will multiply the fraction as you normally do and then have the answer! This is a very simple way to divide frac...
How To: Change fractions to decimals
In this tutorial, we learn how to change fractions to decimals. First, you will need to divide the numerator by the denominator. The numerator is the top number and the denominator is the bottom number. Once you get this number, you will end up with a decimal instead of a fractions. When finished, you will end with the number that will be your answer! Practice doing this with simple numbers, then move onto more difficult to test your mind and get better and better at math! This is an easy con...
How To: Solve quadratic inequalities by factoring in algebra
Looking for a guide on how to solve quadratic inequality problems? 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 free math tutorials, you'll learn how to find the right ans...
How To: Compare methods of solving quadratic equations
In this video the instructor shows the different methods of solving quadratic equations. There are many methods to solve quadratic equations each with its pros and cons, each method suitable for a particular situation. The first method to solve quadratic equation is factoring. The advantage of using this method is that it is quick and easy. But the problem is not all equations can be factored very easily. This method requires a lot of practice and intuition. Use this method when the discrimin...
How To: Normalize a data set into another scale
Comparing evaluations of the same thing done on different scales can seem difficult, but there is a simple equation you can use to translate something expressed in one numerical scale into another. This video will show you how to use it and make your math life easier.
How To: Calculate the growth rate or percentage change between two numbers
The concept of percentage growth or decline is confusing to a lot of people. If you're one of those people, watch this video. It breaks down how percentage change and growth rates work and how you can calculate them from any pair of numbers.
How To: Determine whether you child is performing at grade level in math
Math is arguably the most important subject your children study in school, and making sure they're keeping up is important. If you want to determine whether you child is performing up to their grade level, watch this video. It will give you ideas for ways to test whether that is the case.
How To: Solve quadratic inequalities in calculus
Calculus can be a bit tricky, but don't worry, Watch Math is here to help you out. Watch this math video lesson to learn how to solve quadratic inequalities in calculus. There's no better way to learn mathematics than from an advanced mathematician, like this PhD.
How To: Find how many toothpicks will be needed to form the nth figure in a sequence
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 employ inductive reasoning to determine the number of toothpicks you'll require to generate the nth (e.g., the 50th) figure in a sequence of figures.
How To: Prove that the areas of diagonal-generated triangles are equal in geometry
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 demonstrate that a diagonal line drawn from one corner of a rectangle to another will generate two equivalent triangles.
How To: Find the inverse of a function in intermediate algebra
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 solve problems involving function inverses.
How To: Representing a number as a decimal, percent, and fraction
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 express a number as a decimal, percent and/or fraction.
How To: Describe the meaning of percent in basic mathematics
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 explain what a percentage is within the context of basic arithmetic.
How To: Work with reaction mechanisms in organic chemistry
This free video science lesson from Internet pedagogical superstar Salman Khan presents a general introduction to the concept of reaction mechanisms in organic chemistry. Whether you need help studying for that next big test or could just use a hand finishing your homework, you're sure to be well served by this video lesson. For more information, including detailed, step-by-step instructions, take a look.
How To: Use Markovnikov's rule with carbocations in organic chemistry
In this free video science lesson from Internet pedagogical superstar Salman Khan, you'll learn how to apply Markovnikov's rule to solve carbocation problems in organic chemistry. Whether you need help studying for that next big ochem test or could just use a hand finishing your homework, you're sure to be well served by this video lesson. For more information, including detailed, step-by-step instructions, take a look.
How To: Work with steric hindrance in organic chemistry
In this free video science lesson from Internet pedagogical superstar Salman Khan, you'll learn how to use Markovnikov's rule to understand steric hindrance in organic chemistry. Whether you need help studying for that next big test or could just use a hand finishing your homework, you're sure to be well served by this video lesson. For more information, including detailed, step-by-step instructions, take a look.
How To: Work with SN2 reactions in stereochemistry
In this free video science lesson from Internet pedagogical superstar Salman Khan, you'll learn how to handle SN2 substitution reactions in stereochemistry. Whether you need help studying for that next big test or could just use a hand finishing your homework, you're sure to be well served by this video lesson. For more information, including detailed, step-by-step instructions, take a look.
How To: Represent chiral molecules in organic chemistry
In this free video science lesson from Internet pedagogical superstar Salman Khan, you'll learn how to visualize chiral molecules in organic chemistry. Whether you need help studying for that next big test or could just use a hand finishing your homework, you're sure to be well served by this video lesson. For more information, including detailed, step-by-step instructions, take a look.
How To: Multiply two double-digit numbers with an intersecting lines method
This is an interesting trick to solving multiplication problems. It involves multiplying 2 double-digit numbers with hand drawn, crisscrossing lines.
How To: Calculate the width of a fence given its length and perimeter
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 find the width of a fence when given numbers for its length and perimeter.
How To: Solve the six problem solution
Solving 6 math problems using different methods is the idea behind this video. First, you make three rows of numbers vertically from 1-9. All the numbers match across for example, 1 1 1, 2 2 2, 3 3 3, and so on. Each set of numbers creates a mathematical problem who's solution is the number six. These problems require some thinking to solve. The only one that is immediately apparent is 2 2 2=6 which is, of course, 2+2+2=6, (3x3)-3=6, the square root of 4 =2. This done on all three of the four...