# Hot Education How-Tos

### How To: Remember "greater than" & "less than" symbols

This video shows you how to easily remember "greater than" and "less than" math symbols. The first thing you have to remember is that "less than" symbol looks like the letter L ("less than" symbol is "<"). When you see this sign, remember that < looks like L and means "less than". The other symbol, "greater than" does not look like the letter L, therefore it cannot be "less than" and it's easier to remember. The "greater than" symbol is ">". That's it! Good Luck!

### How To: The Best Investigatory Projects in Science: 16 Fun & Easy Ideas to Kickstart Your Project

Most of us have conducted an investigatory science project without even knowing it, or at least without knowing that's what it was called. Most science experiments performed, from elementary to high school students and all the way up to professional scientists, are investigatory projects.

### How To: Use ">" (greater than) and "<" (less than) symbols

In this video the author explains how to identify the less than (<) and greater than (>) symbols and when to use them. She explains to us to relate the numbers to animals stating that the smaller numbers are smaller animals and bigger numbers are bigger animals. Now she tells us to imagine that smaller animals are eaten up by the larger animals. So she shows a smaller number comes on the left side of '<' sign and bigger number comes on the right side of '<' sign stating that the bigger number...

### How To: Find the Volume of Composite Figures (Also Called Composite Shapes)

Composite figures are composed of several geometric shapes and are three-dimensional shapes. The first composite shape is a combination of a rectangular prism and a pyramid. To find the volume of the entire shape you find the volume of each individual shape and add them together. The second figure consists of a cylinder and a hemisphere. Check out the video below for the full lesson.

### 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: 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: Find the volume of a sphere with radius r

Are you slightly rusty on your math skills? This video demonstrates how to find the volume of a sphere with a given radius. The first step is to sketch a solid and cross-sectional view of your sphere to get an understanding of the process to come. Next, find a formula for the area of this cross-section. Third, find the limits of integration. This will allow you to take the area of each cross-section in the sphere, not just the singular one you are viewing. Lastly, integrate this formula from ...

### How To: Find a number given Its percent

This how-to video is about how to find a number when its percent is given. This video is really helpful and effective in finding the number when the percent is given, the following steps are explained in the video to find the number when its percent is given:

### Make Slime Without Borax: 5 Easy Recipes for Gooey Homemade Ooze

One of the only things I remember from watching Nickelodeon as a kid is the epic green slime. Looking back, I don't know what was so great about it, but every kid my age thought that being drenched in slime would be the coolest thing on earth.

### How To: Make potassium nitrate at home

Believe it or not, there are cheap ways to make potassium nitrate for your chemistry experiments. And the key ingredient… "sodium-free" salt.

### How To: Find the Percent Given Two Numbers

Whether you're shopping for deals, need help with a little math, or any number of other occasions, it's a valuable skill to know how to quickly figure out a percentage given two numbers.

### How To: Make MnSO4 from MNO2 (two separate ways)

What is MnSO4 and MNO2, anyway? They are they molecular formula for Manganese Sulfate and Manganese Dioxide. And you can make one from the other. But how?

### How To: Do long division without a calculator

This video shows you step by step how to do long division without the use of a calculator. The video shows viewers two different ways to solve a division problem. It first shows how to do the problem the traditional way, then it shows how to do it according to the long division process. The long division process is where you write the whole division, multiplication, and subtraction process out showing all your work. Long division is mainly used when dividing large numbers. There are three com...

### How To: Make Potassium Chlorate from Ordinary Household Bleach and Salt Substitute

If you're not just a chemistry nerd, but also a firearms freak and explosives nut, then this home brew chemistry concoction is just what you need for some cheap homemade potassium chlorate. It's a mixture of potassium, chlorine and oxygen (KClO3) and is used for such things as gun primers, propellents, and explosives (when mixed with the appropriate fuel). And guess what? NurdRage is going to show you the steps for this makeshift potassium chlorate.

### How To: Make Water Freeze into Ice Instantaneously

Have you ever seen water freeze instantly? This "Quick Clip" shows some of my personal experiences with making instant ice using a bottle of water supercooled in a freezer.

### 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: Make a Paper Plate Speaker That Actually Works for Under $1

Back in 2007, YouTube user HouseholdHacker posted a parody video on how to make a high-def speaker for under a buck. MythBusters took on the challenge and busted it.

### How To: Make fake blood from iron, chloride, and potassium

In order to make fake blood, for special effects or for Halloween, you will need the following: Potassium Thiocyanate (KSCN), Iron (III) Chloride (FeCL3), which is also known as ferric chloride or may substitute Iron Nitrate (Ferric Nitrate). You will also need water or dihydrogen monoxide.

### How To: Solve temperature subtraction problems (integers)

An educational video from free math tutoring that shows an easy way to calculate differences of temperature. Many times people commit simple mistakes in subtracting temperatures that lead to illogical results. This video explains a very common pitfall and at the same time, clears up an important concept in temperature subtraction.

### How To: Evaluate combinations of functions from graphs

YouTube user NotesCollegeAlgebra teaches you how to evaluate combinations of functions from graphs. You start off with a graph and some functions. (f+g)(-3), (g/f)(0) and (fg)(-6). You start looking at the graph and the first line and you get (f+g)(-3)=f(-3)+g(-3)=3+1=4. (g/f)(0)=g(0)/f(0)=2/-3=-2/3. (fg)(-6)=f(-6)g(-6)=(-3). But then when you want to find out g(-6) you realize -6 is not in g's domain. So the answer to the last equation is that it doesn't exist.

### How To: Make Water Droplets "Levitate" on Water (Using Vibrations)

You can take some really awesome photos of water droplets if you've got a fast enough camera (and flash), but water drops aren't just spectacular as photographic subjects—you can also make them a part of the photographic process by using a water drop as a DIY projection microscope and even a macro lens for your iPhone. But as useful as a water drop can be, it's still way cooler when they're in front of the camera (as the subject). Recently, researchers from the National Autonomous University ...

### 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: 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: 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: 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: 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: 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: Find the area of an oblique triangle using formulas

In this tutorial the instructor shows how to find the area of an oblique triangle using different formulas. To find the area of an oblique triangle there are different formulae. The first formula to calculate the area of a triangle is area A = (1/2) * a * b * Sin(C), where a and b are the lengths of the two sides of the triangle and C is the value of the angle of the triangle that lies in between the two sides a, b. Now substitute these values in the given formula to find the area if you have...

### 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: Add a footnote to a research paper

In this tutorial, we learn how to add a footnote to a research paper. To do this, you will need to have all the sources written down where you got the information for the topics that you're writing about. Make sure you give credit to all the places that you go the information, or else you stole it and it's plagiarized. You will need to write down the author's name, title of the source, publication company, city of publication, copy date, and page number. To add the footnote, you will simply w...

### 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: Cite a website with hard to find author or date info

Sometimes it can be difficult to find information essential to a citation on a webpage, like an author or a date. Here are some steps you can take to make up for this lack of information.

### How To: Make Glow Powder Out of Household Chemicals

Glowing substances have always held a powerful appeal to people, and making new ones can be a lucrative business. If you need some glow powder for a project of yours, watch this video to learn how to make DIY glow-in-the-dark powder out of normal household chemicals.

### How To: Use a TI-89 to calculate nCr

This video shows you how to do a mathematical representation on computing the nCr function using a TI-89 calculator. You can write the nCr notation in different forms. It can be simplified from nCr to C(n,r). The symbol can either be read "n choose r" or "n taken r at a time" which are from it's probability applications. On the example to find "26 choose 17", go to the Home screen of the TI-89 calculator and then go 2nd 5 which is Math. Go choose probability and then to nCr to type in (26,17)...

### 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: 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: Do long division with decimals

Video Nerd thinks that when your doing long division with decimals you should first take out the decimal. Write the number as if it didn't have a decimal. For example if the problem was 12.5 divided by 5 then you will just use 125 and divide that by 5. Next divide the first digit of the dividend by the divisor an write the number up top. Next you multiply, after your done multiplying the numbers subtract, and when your done subtracting the numbers drop the reaming numbers in the dividend down...

### How To: Make "Hot Ice" with Sodium Acetate Crystals

If you've ever used a heating pad or hand warmer, you essentially know what "hot ice" is. It's supersaturated sodium acetate, and it's actually fairly easy to make at home out of sodium acetate crystals. You can also make it out of vinegar and baking soda (directions at the bottom of this article).

### How To: Use the Ultrospec UV-visible spectrometer in the lab

The Department of Biological Sciences at the University of Alberta brings you this video tutorial specifically relevant to your student laboratory courses, specifically microbiology. If you're a student at any school of biology, this information will be helpful for learning how to use the Ultrospec UV-visible spectrometer and HP printer in the lab.

### How To: Make an awesome colored smoke bomb

The video describes an easy at home process for making smoke bombs. The items you will need are as follows: