# Hot Education Posts

### How To: Find the area of irregular shapes

This video explains how to find the area of irregular shapes. Draw the shape on a grid or graph paper. This will help you divide your shape into pieces. Draw dotted lines to divide the shape into squares, rectangles or triangles. For instance, if you have an "L" shape, you can divide the shape into two rectangles. Be sure your shapes do not overlap. Calculate the area of each individual shape. The graph paper will help you determine the length and width of each shape. Add the resulting areas ...

### How To: Make a homemade hot air balloon

Think a hot air balloon is something you can only read about in books? Think again. In this six-part science based tutorial, learn how to make your very own hot air balloon using science & the following easy to find materials: plastic bags, plastic drinking straws, thin candles, aluminun foil, tape, and scissors.

### News: Magnetic Powder Turns Silly Putty into Freakish Magnet-Hungry Blob

It's best known as a children's toy, but kids aren't the only ones who can appreciate the unique and marvelous properties of Silly Putty. It's an incredibly fun silicone polymer that almost seems like a scientific anomaly, thanks to its viscoelastic non-Newtonian flow. This amazing dilatant fluid can be stretched, torn and mashed back together, as well as bounce and shatter into pieces with a forceful blow.

### How To: Make freaky cornstarch monsters dance on speakers

How to make a cornstarch monster in your own home. This non Newtonian fluid will dance on a speaker, creating wild little monsters. The goopy liquid should then be dumped into the speaker head. The wave form you need is a pure Sin wave at 120 hertz.

### How To: Use the flame test to determine an unknown metal

The flame test is used to visually determine the identity of an unknown metal of an ionic salt based on the characteristic color the salt turns the flame of a bunsen burner.

### How To: Solve percent equations

In this tutorial the instructor shows how to solve percent equations. The general form of a percent equations is that a is b% of c. As there can be three kinds of variables a, b, c, the questions involving percent equations can be of three types having one of the three variables unknown. These kind of percent statements can be solved easily by setting up an equation. So, to convert percent statement into a equation replace the unknown term with n, the 'is' term with equals sign and the '%' si...

### How To: Make invisible ink with baking soda and water

Now you see it, now you don't! Team up with the science sleuths of A-TV to make your own invisible ink.

### How To: Find the area of complex figures

In this tutorial the author explains how to compute the area of a complex figure. Now he first defines what a complex figure is by saying that a complex figure is a figure made up of two or more basic shapes. He uses an example to convey his idea and breaks that sample figure into basic squares and rectangles. Now he computes the areas of these individual units separately and finally puts them together to arrive at the final area of the complex figure. If you are looking to compute the area o...

### How To: Make mothballs jump

If you put mothballs in a solution of vinegar and baking powder, the balls will collect air bubbles; then after they cause the balls to rise, the bubbles pop, and the mothballs drop.

### News: Metal Isn't Flammable... Right?

Theo Gray of Gray Matter explains the principle behind sending steel up in flames- as long as it's steel wool, of course. The process is beyond simple. Spend 2 bucks and 2 minutes: purchase a steel wool pad, hold in pliers, light with a match. But the question is, why is steel wool flammable, while other forms of metal are not? Explanation below the video. Theo says:

### 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: 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: Reduce a fraction to its simplest form in basic math

Fractions are numbers of the form a/b, where a and b are integers. Fractions are also called as ratios. Fractions are further divided into proper fractions and improper fractions. Proper fractions are those where the numerator is less than the denominator and improper fractions are those where the numerator is greater than the denominator. As fractions are ratios a fraction can have many equivalent forms. Multiplying the numerator and denominator of a fraction with a same number gives a fract...

### How To: Find the surface area of a regular pyramid

In this tutorial, the instructor shows how to compute the surface area of a regular pyramid. A regular pyramid has four equal sides which are in triangle form, and the base in square form. Its surface area is four times the area of its side plus the area of its base. He goes on and takes an example with sample values and demonstrates how to compute the final value using the formula. He reminds the viewer to use square units in the final answer, as square units equal the area. To find out the ...

### How To: Understand and work with rational & irrational numbers

In this video the instructor explains the concepts of rational and irrational numbers. Multiplying a number by itself gives the value of its square. If you apply the square root to that squared number it returns to you the original number. This square root is also called a radical. A square root of a positive number can have two values. For example the square root of 81 is either 9 or -9; this is because when you multiply 9 with itself the square is 81 and even when you multiply -9 with itsel...

### 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: Write A Letter From Teachers To Parents

Parental involvement is a crucial ingredient in the success of many children. Teachers know the saying all too well that it takes more than a village to raise a child, for one - it takes parental involvement. Thus, it is important for teachers to reach out to parents in that first week of school. Teachers should write a formal letter that is welcoming and easily comprehensible to the parent and the student. This letter should be able to communicate that the teacher values the child’s educatio...

### How To: Solve equations with the order of operations

In mathematics, the order of operations define the priority in which complex equations are solved. The top priority is your parenthesis, then exponents, followed by multiplication and division, and finally addition and subtraction (PEMDAS). This video tutorial demonstrates the order of operation with various examples and explains the associated methodology. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autod...

### How To: Turn Milk into Strong Natural Glue with Baking Soda and Vinegar

You can do all kinds of unexpected things with milk, like make your own pore strips and invisible ink, or even get rid of red wine stains with it. But did you know that you can also use it to make your own glue?

### How To: Make Black Snake Fireworks With & Without Fire

In this video, I'll be showing you how classic black snakes work and how to make them at home. There are actually two methods covered in the video — one that uses fire and one that does not. So just choose the one that fits best for your situation.

### How To: Make Your Own Homemade Glow Sticks

Glow sticks, a popular favor at parties and outdoor events, and a must-have on Halloween, can be traced back to the United States Navy in the mid-1960s. The military desired improved visibility during night operations, and glow sticks, with their small-size portability and lack of batteries, were a perfect tactical solution.

### 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: 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: 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: 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: 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: Figure out the domain & range of a piecewise function

Need to calculate the domain and range of a graphed piecewise function? 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: Make DIY Nitrogen Triiodide from ammonia & water purification iodine crystals

Nitrogen Triiodide is a very powerful contact explosive, but like most fun chemicals is not readily available to the general public cheaply. If you want some and have some chemistry skills, watch this video to learn how to make Nitrogen Triiodide at home out of household ammonia and water purification iodine crystals.

### 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: Measure the volume of a balloon

Here we will demonstrate how to measure the volume of a balloon. A balloon is not a straight edged polygon shape, usually, so the mathematical equations get that much harder, on the flip side, it may be a spherical or ovalish shape, but measurements with math alone are detrimental due to the uneven sizes of the balloon. Here is how to do it properly. You will need a bucket, preferably, to hold water, a larger container than your original bucket, and a measuring container. Place the bucket ins...

### 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...

### News: 10 Amazing Optical Illusions

This video is compilation of ten amazing optical illusions: Rooftop Illusion, Color Illusion, Motion Binding Illusion, Crazy Wire Illusion, Duck-Rabbit Illusion, Silver Egg Illusion, Anamorphic Illusion, Water Illusion, Animated Optical Illusion.

### 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: 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: Prove a triangle inscribed in a circle is right angled

When a triangle is inserted in a circle in such a way that one of the side of the triangle is diameter of the circle then the triangle is right triangle. To prove this first draw the figure of a circle. Now draw a diameter to it. It can be any line passing through the center of the circle and touching the sides of it. Now making this as the side of a triangle draw two lines from the ends of the diameter to a point on the circle. Now join the center of the circle to the other vertex of the cir...

### 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: Create a small explosion with calcium carbide

In order to create an explosion, using Calcium Carbide, you'll need the following: calcium carbide, water, a dropper, and a lighter.

### How To: Detect poisonous arsenic levels using the toxicological Marsh test

Was Napoleon's death really due to stomach cancer, or was it arsenic poisoning? Some scientist believe the latter. Arsenic poisoning was a deadly weapon in that era, because it was undetectable when administered over a long period of time, making murder seem like natural causes. But if arsenic (As) is poisonous to most multicellular life, then what's with the newest NASA discovery?

### How To: Translate a sentence into math symbols

We will be translating the sentence "twice y differs from 5 by more than two, “into a mathematical equation. The word twice generally means two times, so 2*y (because y comes next in the sentence). Differs normally means is different and a difference from something in a mathematical sentence means subtraction most of the time, thus minus five. We don't know if we’re talking about below 5 or above 5 on the number line, so we put absolute value around the equation. More than implies a greater t...

### 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...