### 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: 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: 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: 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: 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: 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: 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: 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 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:

### 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: 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: 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: 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 formula of a piecewise function given a graph

This video shows how to find the formula of a piecewise function when given a graph. The first step is to write a definition for the graph, which is done by identifying the different domains shown in the graph. The second step is writing formulas for each domain specified by the lines in the graph. The point-slope formula is used to identify the slope and y-intercept for the leftmost domain, which has a sloped line. A point and horizontal line make for simpler equations in the other pieces of...

### 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: Find the volume of a swimming pool

In this video, we learn how to find the volume of a swimming pool. To do this, you will first need to find the measurements of all the sides that are on the pool. After this, you will plug in the measurements that you found into the equation to find the volume. This equation is: V=AH, volume= area(height). So, plug in the area and the height to the equation for A and H and then multiply these two together. Once you do this, you will find the answer! Don't forget to label the units on the fina...

### How To: Weather Forecast And Weather Predict Without Technology

We have no control on the weather yet it is a part of our lives which influence what we do, what we eat, what we wear and many times where we live. How did people predict the weather before there was the Internet, television, radio or the weatherperson with all of their gadgets?

### 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 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: 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: 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: 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 & perimeter of triangles & squares

When you are figuring the area of a square, you only need to know the height and width of the shape. Once you know the height and width, multiply them to get the area of the square. To find the perimeter of the square, add all four sides together. To find the area of a triangle, multiply together two of the sides (not the hypotenuse) and then multiply that figure by 1/2. To find the perimeter of the triangle, add all three sides together.

### 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 and sketch the domain of a multivariable function

Looking for a primer on how to find and sketch the domain of a function z = f(x, y) in calculus? Learn how with this free video calc 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: 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: Write a sum/difference of logarithms as a logarithm

To write the sum or difference of logarithms as a single logarithm, you will need to learn a few rules. The rules are ln AB = ln A + ln B. This is the addition rule. The multiplication rule of logarithm states that ln A/b = ln A - ln B. The third rule of logarithms that deals with exponents states that ln (M power r) = r * ln M. Using these three rules you can simplify any expression that involves logarithms to arrive at a single logarithm. The instructor shows how to apply these rules to a f...

### How To: Make This Amazing 9-Layer Density Tower from Things Found in Your Kitchen

Ralph Waldo Emerson once observed that "the seed of science" was "wonder," and taking a look at this nine-layer liquid tower from Steve Spangler's Sick Science! channel, one can't help but do just that — wonder. How is this possible? Is this magic or what?

### 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 the value of a variable in an algebraic equation

Need help figuring out how to solve simple algebraic equations? 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: Factor trinomials with the "swing method"

This is a very interesting educational video on how to find the factor trinomials using the swing method. Let us take an example and find the factor trinomials for 2xsquare-13x-45. Let us use the swing method. So now we will get 2xsquare -13x-45. You have to find the suitable factors of 90. It is 18 and 5. If you multiply 18 by 5 you will get 90. You will get (x-18over2)(x+5over2). The final answer is (x-9)(2x+5). Now we have found out the factor trinomials of 2xsquare-13x-45. This swing meth...

### 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: 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: 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 a permanent, reusable glow stick

Make a reusable glow stick, glow-in-the-dark-style! Imagine, you'll never have to buy one of those ChemLite's again, because you can reuse this homemade glow stick over and over again. This video tutorial will show you how to make a permanent, reusable glow stick. The materials in this experiment are simple: epoxy resin, straw, and some phosphor powder.

### 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: Find the equation of a circle given: center & tangent

In this video, the instructor shows how to find the equation of a circle given its center point and a tangent line to it. To do this, take a graph and plot the given point and the tangent on that graph. Now, from the center of the circle, measure the perpendicular distance to the tangent line. This gives us the radius of the circle. Using the center point and the radius, you can find the equation of the circle using the general circle formula (x-h)*(x-h) + (y-k)*(y-k) = r*r, where (h,k) is th...

### 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.

### 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.