# Hot Education Posts

### How To: Make fireballs you can hold in your hand

This flame you CAN hold, without burning your skin off. Learn to make fireballs you can hold in your hand. This amazing video tutorial shows you how to do it. All you'll need for this little science experiment or fiery weapon is 100% cotton cloth, scissors, lighter fuel, cotton string, and a needle. Be careful to follow the directions in this how-to video carefully otherwise you'll really be playing with fire.

### 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: Find a missing side of a triangle, similar to another

In this tutorial the author shows how to find out the missing side of a triangle which is similar to an other triangle. He explains the concept of similar triangle using diagrams and by showing that similar triangles have equal corresponding angles and parallel sides. Now he labels sides of similar triangles and intends to find out the length of unknown side. Now in similar triangles, as the lengths of sides are proportionate he shows how to write a equation of proportion and solve it finding...

### How To: Use a Peltier module to create free electricity from heat

A Peltier module allows you to turn heat into electricity. Because you can place it in areas that are normally warm anyway, the electricity created is "free" in a sense, though it does work best when one side of the module is cold and the other is hot. In other words, all you'll need for this project is the Peltier module and a cooler surface such as soil or water, and a warm area such as a well lit window or warm pan.

### How To: Learn Calculus in 20 minutes

Did you sleep all semester in your Calculus class? Are you just waking up now to realize you have a test on Monday and that you're totally screwed? Well, luckily you can learn an entire semester worth of Calculus in just twenty minutes... or at leasts that's the hope.

### How To: Find Leg Lengths and Hypotenuse of a 45 45 90 Triangle

A 45 45 90 triangle is a special right triangle because you can use short cuts to find leg length and hypotenuse length. This video solves two problems involving leg length and hypotenuse length.

### How To: Make Soap Out of Guava Leaf Extract for a Science Investigatory Project

Unless you're a high-schooler building a nuclear fusion reactor, the hardest part of a science investigatory project often is coming up with a good idea. You want it to be cool yet feasible, novel but still useful.

### How To: Do normal probability calculations on a calculator

Probability computation is a complex process and even using a calculator can be difficult. But normal probability calculations can be performed quickly with the help of calculator once you know how to use it. So when you have to calculate a probability from a normal distribution you can use the functions on your scientific calculator. You can use the normal CDF function from you calculator to compute the area under a normal curve. The function requires lower band and upper band values, the me...

### How To: Square expressions involving radicals

Here we look at squaring expressions that involve radicals because people tend to make some common mistakes while solving such expressions. Take 5 times the square root of y quantity squared, the answer here is not 5y. Here's the reason, square means to multiply something with itself so the square of 5 root y would be 5 root y into 5 root y. So 5 x 5 is 25 and under root y into under root y equals just y so the answer will be 25y.

### How To: Turn water into ice without a freezer

Here's a fun experiment you can do that will demonstrate the effects that pressure has on the freezing point of a liquid. You will amaze your friends as you do what seems to be impossible, turning water into ice without sticking it in the freezer.

### How To: Use a mean and scatter plot for Statistics

Wondering how to use a mean and scatter plot for statistics? Just follow the few simple steps as below.

### How To: Multiply proper & improper fractions

So, you need a little extra help in the fractions department? No problem. In this two-part vieo tutorial, learn how to multiply proper fractions and mixed numbers in part one. In part two, learn how to multiply mixed numbers & multiply sets of improper fractions.

### How To: Isolate the sugar in a can of soda

In this video from ScienceOnTheBrain we learn how to isolate the sugar in a can of soda. To find out how much sugar is in soda, pour a can into a pot and boil it until all the water is gone. You will be left with the sugar, and then you can weigh it. First weigh your pot before pouring the soda in. Now boil the soda on the stovetop. When the water evaporates, you'll be left with a syrupy sugar. A can of soda has 39 grams of sugar in it. That equates to about 7 1/2 teaspoons. Fruit juice conta...

### 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: 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: Hollow out a penny

In this video, we learn how to hollow out a penny. First, you need pennies that are dated after 1982, muriatic acid, a plastic container, and sandpaper. First, rub the edge of the penny on sandpaper until the silver color is exposed. Do this on two pennies, then place them in the plastic container. Now, while wearing gloves, pour the acid into the container so the pennies are completely covered. Now the pennies will start to bubble, leaves these in the acid for around six hours. Next, pour th...

### News: Dissecting a Human Head Through Anatomical Illustrations

Human anatomy is something every physician must undergo as a medical student. Some move on to become great doctors, some move on to become great artists, helping to better educate students and improve upon many illustrated representations of the human body since the days of medieval medicine. But thankfully, you don't have to be in the medical profession to enjoy the beautiful art of the human body created for teaching purposes.

### How To: Make ammonium nitrate with NaHSO4 and nitrate salt

Okay, so you don't necessarily have to make ammonium nitrate to have ammonium nitrate — ammonium nitrate can simply be obtained from fertilizers and instant cold packs. Making homemade NH4NO3 can be much more expensive then buying it, but this video is not meant to be a viable route, it's an exploration of science and chemistry.

### How To: Find the volume of a cone quickly

For people who are interested in math or who need to know how to find the volume of a cone for any reason, whether it be homework or architecture, this video will show you how to do so. The formula for finding the volume of a cone is (1/3) pi x radius^2 x height. You can find the radius of your cone by finding half the length across the center of the circle which is the cone's base. After plugging in all the values into this equation, you will be able to find the volume of any cone when given...

### How To: Convert grams to moles for chemistry

310tutoring shows viewers how to easily convert Grams to Moles for Chemistry. If you have 120 grams NaOH and we want this in moles we need a periodic table. Now, you need to figure out what the mass is of each individual element in NaOH. You need the mass of Na, O and H. Na mass is 23, O has 16 and H is 1. Add all of these up to get the molar mass of NaOH is 40 g/mol. Now use this to convert 120 g to moles. Now take 120 grams NaOh and multiply this by 1 mol NaOH/ 40 grams NaOH. You can cancel...

### How To: Get your official SAT score from College Board online

The SATs are a very valuable college entrance test and could determine if you're accepted or denied to your favorite university. So, once you've learned to ace the SATs and have already taken your test, get your scores as soon as they're out! Don't sit in dreaded anticipation— go to College Board and get your SAT test results now!

### How To: Make a ferro fluid

In this video, we learn how to make Ferro fluid. This is a magnetic fluid that you can easily make at home. To do this, you will need: laser jet toner, rare earth magnet, and some vegetable oil. Now, pour the toner into a cup (50 ml), then put 2 tbs of vegetable oil into this cup as well and stir it together until you have a thin consistency. Now, transfer into a smaller jar so you can handle it easier. Now test this fluid by taking the earth magnet and putting it to the bottom of the jar. No...

### How To: Properly cite a website in MLA format

Plagiarism is a serious offense, even if you are copying from the web. With this tutorial, learn how to cite websites properly using MLA format and avoid any trouble.

### 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: Make electricity from copper, zinc and water

Check out this kitchen table science experiment on how to make electricity from copper, zinc and water. You can make your own battery to power a small LED light from just nails, copper wire and water.

### How To: Write rational expressions in lowest terms

In arithmetic, the simplest expression is far preferred to the long eye-boggling one. Stop making your expressions painful optical illusions by watching this tutorial on how to write rational expressions in the lowest terms.

### 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: Rationalize a denominator that contains a surd

In this video, we learn how to rationalize a denominator that contains a surd. First, you need to rationalize the denominator by removing any square root sign. To do this, you will multiply the fraction but the flip of the denominator over itself, with the square root. Then, you will multiply the top by the bottom with the square root and this will remove it from the equation once you do the math to multiply it out. Once you're done, the number will be rationalized and you will have the answe...

### How To: Revise Body Paragraphs

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### How To: Make nitrogen triiodide

Learn how to make nitrogen triiodide (NI3), the main ingredient of the small, paper-covered parcels that you throw at the ground to make a snapping noise, with household chemicals and items. This chemical is very unstable, so please exercise caution.

### 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: Experiment with hydrostatic pressure

This how-to video explains the hydrostatic pressure.

### How To: Fold a model rocket parachute

Lots of newbies ask about this. Don't know why, but okay, here's how to do it -- folding a parachute for a model rocket.

### How To: Harvest Squid Ink

This is an Instructable by canida on how to harvest squid ink. Clean your own squid, and collect ink for printing or cooking!

### How To: Find the arc length of a function

In this tutorial, we learn how to find the arc length of a function. All you're doing when finding arc length is finding the curve between 'a' and 'b'. Imagine this as a string you're pulling straight to see how long it is going to be. The formula says if your function is in 'y=x' you have to take one times the derivative squared. This is a basic formula that you will use to find the arc length. When you plug in your values to this equation, you will find the answer. Practice with the example...

### How To: Multiply mixed numbers with whole numbers

This video shows us how to multiply mixed numbers with the whole numbers. First thing you need to do is to change the mixed number into an improper fraction by multiplying the denominator with the whole number and add the resulting number with the numerator. The resulting number will be placed as a numerator with the denominator being the same. Next, is that we can't multiply a fraction with a whole number. So we need to change the whole number into a fraction and this is done by putting the ...

### How To: Make Vitriol (Sulfuric Acid) Using the Oxidizing & Electrochemical Methods

If you've been following the news lately, you've probably heard of the word "vitriol" being used as a political weapon, with people like celebrity left-winger Jane Fonda blaming conservatives like Sarah Palin for "vitriolic" attacks on Democrats and the "violence-provoking rhetoric of the Tea Party" movement for the recent Arizona shooting.

### How To: Know if matrices can be multiplied

In this Education video tutorial you will learn how to know if matrices can be multiplied. If the column of the first and the row of the second match, you can multiply them. For example if, matrix A has 2 rows and 3 columns (A: 2x3) and matrix B has 3 rows and 4 columns (B: 3x4), then you can multiply them. But, if A: 3x2 and B: 3x4, you cannot multiply them. The shape of the resultant matrix will be the shape of the outer numbers. For example, we saw that if A:2x3 and B :3x2, then they can b...

### How To: Solve word problems involving domain and range

See how to find the domain and range of a function implied by a word problem with this free video math lesson. 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 tutor...

### How To: Make simple and fun "hot ice" at home with vinegar

Hot ice is a very cool experiment. This is a recipe for homemade 'hot ice' that mimicks the sodium acetate one but only requires simple ingredients!