Hot Education Posts

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: Calculate Type I (Type 1) errors in statistics

Need a quick primer on how to solve type-1 error problem in stats? Let this video be your guide. 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. For all of the details, watch this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials.

How To: Build a real lava lamp

This is how to make a near professional grade lava lamp. We did this as a chemistry project. We perfected it in a week. This took many hours to do, as we had to get the density just right. We remade it three times, also. At the very end, we combined all of the wax into a huge flask. And then it blew up.

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: 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.

How To: Make liquid sculptures from a handwarmer

Learn how to make liquid sculptures from a hand warmer in simple steps. First buy an instant reusable hand warmer which has sodium acetate in it and keep it ready. Now use 4 packets of the hand warmer and stir them out with water. Transfer them to a bottle and keep it aside. Take a sodium acetate crystal from a used hand warmer and place it in a plate. Now pour the liquid slowly on the crystal and you can see the liquid turns solid as you pour it. Design your masterpiece using all the liquid....

How To: Make slime for kids

Any time is the right time for slime! In this video tutorial, you'll learn how to whip up a nauseating glop of green goo. It's actually a remarkably simple process, requiring just a few basic steps and materials you probably already have around the house. So get to work, and then get sliming!

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.

News: World's Simplest Electric Train

The trick in the video is that the magnets are made of a conducting material and they connect the battery terminals to the copper wire, so the battery, magnets and copper wire make a circuit that generates a magnet field just in the vicinity of the battery. The geometry means the two magnets are automatically at the ends of the generated magnetic field, where the field is divergent, so a force is exerted on the magnets.

How To: Experiment the law of inertia

Newtons proposed the concept of inertia. According to him an object at rest tends to stay at test and an object in motion tends to continue in motions unless acted up on by an external force. This is the principle of inertia. The tendency of the body to continue to stay as it was is called its inertia. You can demonstrate this principle with a simple experiment. As shown in the video when the hoop is pulled out the pen cap falls in to the bottle. Here the hoop is acted upon but the cap is not...

How To: Test if a high-voltage diode is functioning properly using direct current

If your microwave oven is broken, it might be because the diode has gone bad. If you think that may be the culprit, you might want to test it. In the hobbies world, high-voltage diodes are often used to make high-voltage power supplies, but if you take it from a broken microwave oven, this video will show you how to test the diode for proper functionality using a direct current (DC) power supply.

How To: Convert temperature measured in Celsius to Fahrenheit

This video teaches how to convert a value in Celsius to Fahrenheit in simple steps. First take a paper and marker and keep in mind a Celsius value (e.g-32) to convert into Fahrenheit. Now use the formula to convert Celsius to Fahrenheit which is F=1.8(32)+32. Use a calculator to calculate the formula and you will get the result as 89.6 Fahrenheit. Now round it off the and your final result will be 90 degree Fahrenheit.

How To: Make hydrochloric acid from salt

In this tutorial, we learn how to make hydrochloric acid from salt. First, you will pour some salt into a distil flask. After this, you will add in some concentrated sulfuric acid to the salt. Next, you will let these react with each other. You will start to see gasses bubble up and the excess hydrogen chloride gas come out through the top of the tube. To create a stronger reaction, you can add heat underneath the reaction. Then, test this by exposing it to ammonium chloride. If it's the righ...

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: 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: 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 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: 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: 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 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: Calculate the height and volume of a pyramid

Need to know how to calculate the height and volume of a pyramid in geometry? Learn how with this free video 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).

How To: Determine the age of a fossil using carbon-14

If you have a fossil, you can tell how old it is by the carbon 14 dating method. This is a formula which helps you to date a fossil by its carbon. If a fossil contains 60% of its original carbon, how old is the fossil? The half life of carbon 14 is 5600 years. That means this is how long it takes for half the nuclei to decay. After 5600 years, if we start with a gram, we end up with half a gram. This rather complex formula shows you how to solve this puzzle using accepted scientific methods.

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!

How To: Write a logarithm as a sum or difference of logarithms

This video shows the method to write a logarithm as a sum or difference of logarithms. The square root of the term given is taken out as half according to the rule. Then the numerator and denominator is divided into product of factors. This is broken into the difference of numerator and denominator according to the rule. Finally, the product of factors is expressed as the sum of factors. Now we see the domain of the term. As the term is a square root of the term it should be greater than zero...

How To: Isolate a variable

If you're struggling a bit with algebra, check out this video to learn how to isolate a variable. Isolating a variable is a matter of separating and simplifying.

How To: Focus your laser to make it burn

In this video, we learn how to focus your laser to make it burn. The best spot for a laser to burn things is at its focal point. This is where the beam from the laser is at its smallest. If you hold a match in front of the beam, it will light it on fire as soon as it's in front of it. If you put two lasers next to each other going the same direction, it won't be able to burn because the light beam is too large. If you position the lasers so the light is smaller, then they can catch something ...