# Hot Education Posts

### How To: Find the 100th term in a sequence

Need to find the nth term in a given arithmetic sequence? See how it's done with this free video math lesson. Need help finding the 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 seri...

### How To: Build and make an erupting volcano model at home

Hmm... wondering what to do with a lazy Sunday afternoon? Why not build a volcano that can erupt? Have fun and make a mess, all in the name of science!

### 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: Find density using the water displacement method

To find out the density of any given object there is a simple equation, mass divided by the volume equals the density. In this video a lady is showing how to get the volume of three objects using water. First the objects are measured on a scale to find out how much they weigh, the mass. Next each one of the objects is placed into a measured amount of water to find out the volume. Before you place the object into the water you will want to know just how much water in there. That way when the o...

### How To: Make potassium nitrate from instant cold packs

Watch this science video tutorial from Nurd Rage on how to make potassium nitrate from instant cold packs and potassium hydroxide.

### How To: Determine the density of salt water

Everyone floats in the Dead Sea because the amount of salt in water effects the density. Do a hands-on experiment and practice checking density. Here’s a good science experiment to do in class or at home, if you have access to an electronic balance.

### How To: Translate a shape

Learn how to translate shapes with a few simple steps. - First step: Find the new verticals under the transformation which are T3,2. Values are A=(-5,-8), B=(-3,-4), C=(-8,-3), D=(-6,1). Find the points of the verticals on the graph and connect the points one by one until you can get one shape.

### How To: Solve basic linear function word problems in algebra

Need some help solving linear function word problems? See how it's done with this free video math lesson. Need help finding the 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 o...

### How To: Determine if lines are parallel or perpendicular

In this tutorial, we learn how to determine if lines are parallel or perpendicular. You will be given two straight line equations. First, remember that parallel lines have equal slope, identical to each other. Perpendicular lines have negative reciprocal slopes. For example, 2/3 and -3/2 would be a perpendicular line. If you think of parallel lines, then you can graph them to see what they look like when written down. Then, graph the other lines to see what they look like as well. Once you un...

### How To: Understand how metals react in hydrochloric acid

In this video tutorial the instructor talks about Hydrochloric acid (HCL) and how it reacts to a few metals. To try this out take 30 ml of concentrated hydrochloric acid in a beaker. You need to employ caution while handling acids, especially if you use strong ones. Now you can throw small pieces of different metals into it carefully to see how it reacts with different metals. For instance when this HCL comes in contact with metals various reaction take place depending up on the metal. Like i...

### How To: Figure out a tip without a calculator

To figure out a tip without a calculator, first remove the pennies amount in the bill. For example, if your bill is $23.76 becomes $23.70. To figure out a 10% tip, move the decimal point one place to the left. So, 23.70 becomes 2.370 or $2.37. Bump up that number to $2.30 or $2.40 or $2.50 cents, depending on your preference. Since 20% equals two times 10%, double the figure you computed for 10%. So, $2.30 becomes $4.60, or $2.40 becomes $4.80 or $2.50 becomes $5.00. Using this method, you wo...

### How To: Launch a Camera into Space (On a Shoestring Budget)

Earlier this month, Adam Cudworth, 19, launched a camera attached to a weather balloon into the edge of space. Battling tough winds, freezing temperatures, atmospheric pressure and tumbling speeds, the teenager from Worcestershire, England was able to capture these amazing pictures of the Earth's upper stratosphere. How to Send a Camera into Space

### 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: Take an acid and base to make salt

In this tutorial we learn how to take an acid and base to make salt. To start, you will first need to take an acid of your choice, this can be something like vinegar. After this, you will combine the acid with a base and then wait for it to react. Once it starts to react, gases will release from them and you will end up with some salt! Be sure to put a cap on the container while the reaction is happening. This will allow the reactions to come together and the gases to react. Have fun and do t...

### How To: Deal with brackets in polynomials

This how-to video shows viewers how to solve math problems with brackets in polynomials. The person in the video teaches people how to solve the problem with a positive sign before the brackets. This segment does not show how to solve the trickier problem where there is a negative sign in front of the brackets. The tutor shows everything from removing the bracket due to the positive sign, to combining the similar terms for the result of the problem. This video can help anybody deal with brack...

### How To: Deal with brackets in polynomial fractions

When dealing with brackets in polynomial problems the first thing you need to notice is if there is a negative sign before the bracket. If there is not then all you need to do is get rid of the bracket and combine similar terms. If there is a negative sign then you need to multiply everything inside the bracket by a negative 1. This will change all of the signs inside the bracket. This video is a quick demonstration that will help you when completing these problems.

### How To: Make nitric acid

Watch this science video tutorial from Nurd Rage on how to make nitric acid. They show three ways to make nitric acid based on two different chemical approaches, both of which can be done using easily accessible materials.

### How To: Build a Simple Paper Bridge as a Science Experiment

Every day we pass bridges, whether it's a foot bridge, a highway overpass, a span over water, or a viaduct over a valley. We pass on these structures without even thinking of the engineering genius that went into their design and construction, let alone the science behind their strength.

### How To: Make a crazy foam explosion science experiment

Check out this video to see our Fantastic Foamy Fountain in action. The experiment uses Hydrogen peroxide and dry yeast. Hydrogen peroxide is similar to water but it has an extra oxygen atom. This makes it more dangerous and only adults should handle the hydrogen peroxide.

### How To: Calculate percent composition for chemistry

To calculate percentage composition we will take the example CO2 it stands for Carbon-Di-Oxide. It is the composition of Carbon and Oxygen. We have one carbon and its weight is 12.01 and 2 oxygen. So, we will multiply 2 with 16.00 which is the weight of the oxygen.

### 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: 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: Find the area of a circle when you know the diameter

In this video, it is shown how to calculate the area of a circle where the diameter is given. The formula for calculating the area of a circle is pi multiplied by square of radius. Radius is actually half of the diameter. In this video, the diameter is given as 10.6 meters. Hence, the radius will be half of 10.6 which is equal to 5.3 meters. Now, to find the area we shall multiply pi with the square of 5.3. Square of 5.3 is 28.09. If we multiply 28.09 with pi we shall get the area of the circ...

### How To: Make elephant toothpaste with detergent, hydrogen peroxide & potassium iodide

We all know what elephant toothpaste is, but what's the best way to make this massive growing foam? Dr. Lithium from NurdRage has answers. He'll show you the best way to reproduce this chemical reaction to get the best foaming action! This is a classic science class demonstration.

### 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: 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: Solve for the missing ratios or proportions

In this video the tutor shows how to solve the missing ratios or proportions. He explains it with an example, where a number in one of the ratios is missing and he intends to find this value. He shows the example of cross multiplication, where you multiply the values on the either side of the equation diagonally and finally solves the equation which results in the value of the unknown value. This is an introductory video explaining how to use rations and proportions to find missing values.

### How To: Find extra points for a parabola (quadractic equation)

This is a mathematical educational video on how to find extra points for a parabola. In the first two examples there is no need for finding extra points as they have five points and have zeros of the parabola. In example 3 we need to find extra points. The equation is y=4xsquare-4x+4. You can take x= -1 and get the value for y. You will get a point now. Similarly you can substitute -2 for x in the same equation and get the value for y. Now you get another point. Now you can draw the parabola.

### How To: Multiply & Divide Numbers (Basic Elementary Math)

Adding and subtracting may be the easiest of mathematical operations, but once you get it down, multiplication and division can be just as easy. That's why it's called elementary arithmetic. If it were harder, it would be called college algebra or trigonometry. But it's not— it's basic math, and once you get your head around the numbers, you'll never hate math class again! (Okay, maybe you will.)

### 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: 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: Find the area of a triangle when given 2 sides & angle

This video shows you how to easily find the area of a triangle when you know the length of 2 sides and the angle between them. The first thing you have to do is mark the sides of the triangle by a, b, c, where a is the side between A and B, b is the side between B and C and c is the side between C and A. If you know 2 of these 3 sides an you know the angle between them you can find the area of the triangle very simple: Area= (a x b x sin c)/2, where a, b are the two sides and c is the angle b...

### How To: Make an erupting volcano with baking soda and vinegar

If you love action and adventure then you've come to the right place. Get ready for a red-hot science explosion as the A-TV science superstars show you how to make your very own erupting volcano!

### 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: Solve algebraic equations with the y = mx+b format

This video shows us how to solve algebraic equations with the y = mx+b format. When talking about solving y=mx+b format, it’s about solving linear equations so that y is on one side and with some terms x on the other side. Here in this equation 'm' is actually the slope of the line and slope= (rise/run) and it is interrupted with the term 'b'. This can be explained by taking an example of the same format. In the example 2x+3y=9, we need to shift the term '2x' to the other side so that the equ...

### How To: Calculate probability in "at least one" problems

Calculating probablities can be used to help us make decision. PatrickJMT explains how to calculate probability in an "either A or not A" scenario. The probability of A plus the probability of not A is equal to one. Therefore, the probability of A is equal to one minus the probability of not A ; P(A)= 1 - P(not A). The probability of a major earthquake in San Francisco over a period of time is used as an example. The probablity of an earthquake of a magnitude of 7.5 or greater in San Francisc...

### How To: Make oxygen from permanganate and hydrogen peroxide

C For Chemistry delves into the chemistry of science experiments. This chemist knows what he's talking about. These chemistry experiments are not only fun, but very educational for all of those interested in scientific chemical reactions and properties.

### How To: Find the coordinate of a point

In this video the author shows how to plot a point on the coordinate plane. He explains about the coordinate plane and shows how to read and write points to it with an example. He says that any point on the coordinate plane has an x, y- coordinate values. He says that for any point its projection on the x-axis is its x-coordinate and the points projection on y-axis is its y-coordinate. He shows how to find this out for a sample value and plots the coordinates of it. In this video the author u...

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

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

### 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!