### 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 percent given two numbers

This how-to video is about how to find the percent when two numbers are given. To find the percent of two numbers just follow these steps:

### How To: Make elephant toothpaste with detergent, hydrogen peroxide & potassium iodide

We all know what elephant toothpaste is, but what's the best way to make this massive growing foam? Dr. Lithium from NurdRage has answers. He'll show you the best way to reproduce this chemical reaction to get the best foaming action! This is a classic science class demonstration.

### 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: 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: Make (non-Newtonian) Oobleck from corn starch & water

Mr. O shows his audience in this video how to make oobleck, a slime-like substance which has a variety of unique properties. For this project, you will need a mixing bowl, food coloring, corn starch, a measuring cup, and water. First, color the water with food coloring to a color which is much darker than the color you would like. You will need the correct ratio of water to cornstarch, in a 1 to 2 ratio. Add some water to the bowl and add the cornstarch, then add the rest of the water. Finall...

### 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 ingredientâ€¦ "sodium-free" salt.

### How To: Make simple dark green slime without borax

Most folks mistakingly think that slime - or green silly putty - simply can't be whipped up without borax. But the buffer solution can easily be replaced by another ingredient that you already have lying around in your house: laundry detergent.

### 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. Of course, the first thing I did was beg my parents to buy me some fake slime, but I never knew I could've easily made my own at home. One of the most common ways to make slime is to combine liquid glue with water and a household chemical called borax. ...

### How To: Find the Slope Given 2 Ordered Pairs

Slope is the change in Y over the change in X. Written out, the formula looks is as follows: (y2-y1)

### 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: 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.

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

The first glow sticks were patented by the US Navy in the 70s, but back then, they were called "Chemiluminescent Signal Devices." Today, glow sticks are still used by the military, emergency services, campers, divers and, of course, ravers. I may be done with the glow-in-the-dark parties from my college days, but I still think glow sticks are pretty legit, and always thought it would be awesome to make some for myself. Talk about a cool application for all those boring chemistry lectures.

### 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: 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: Make a crazy foam explosion science experiment

Check out this video to see our Fantastic Foamy Fountain in action. The experiment uses Hydrogen peroxide and dry yeast. Hydrogen peroxide is similar to water but it has an extra oxygen atom. This makes it more dangerous and only adults should handle the hydrogen peroxide.

### 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: 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, letâ€™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: Use baby powder to reveal latent fingerprints

This short video shows us how to reveal latent fingerprints on a glass surface by dusting. Anyone interested in forensic science would enjoy trying it as it shows simple steps in dusting and lifting fingerprints. It does not require any chemicals and we can do it with baby powder. The steps involved are so simple and easy to follow that even kids can try it out for fun. This gives a clear idea about fingerprints on different objects like porous, non porous and metals. Enjoy viewing and detect...

### How To: Find the area of a circle when you know the diameter

In this video, it is shown how to calculate the area of a circle where the diameter is given. The formula for calculating the area of a circle is pi multiplied by square of radius. Radius is actually half of the diameter. In this video, the diameter is given as 10.6 meters. Hence, the radius will be half of 10.6 which is equal to 5.3 meters. Now, to find the area we shall multiply pi with the square of 5.3. Square of 5.3 is 28.09. If we multiply 28.09 with pi we shall get the area of the circ...

### 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: 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: Properly hold a pencil for better handwriting

The fastest and easiest way to improve your handwriting is to learn to hold your pencil properly. A lot of people bypass this seemingly small step and then wonder why their writing looks like chicken scratch. This video will show you exactly how to hold your pen or pencil for the best writing results. This is especially helpful for teachers or parents wishing to help their child develop good writing habits for life. So, grab a pencil and follow along - you will be writing up a storm in no time!

### How To: Round a decimal number to the nearest tenth in basic arithmetic

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. With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to round a decimal number to the nearest tenth.

### 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 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: 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: Find the slope from a set of points

To find the slope of a line you must have two points and then you must plug in the two points into the slope formula. The slope formula is m= y2-y1 over x2-x1. If the slope is a fraction be sure to reduce to the lowest. Remember if a number is divided into zero it is zero, if zero is divided into the number it is undefined. A calculator can help one remember this. Horizontal lines have slopes and vertical lines do not. Drawing the lines on a graph can help you see the actual slopes and which ...

### How To: DIY Ninja Turtle Ooze! Make Your Own Radioactive Canister of Glowing Green Slime at Home

There's a broken canister of mutant ooze leaking down into the sewers! But don't worry because this sticky slime is non-toxic, and it's so easy to make, a three-year-old can do it!

### How To: Spend Money on a Graphing Calculator? Nahâ€”Just Use This Web-Based TI Emulator

For the majority of my math classes in middle and high school, a graphing calculator was a must. While the calculators were very useful to have, they were quite steep in the price column. After losing the TI-83 graphing calculator my parents bought me in high school, I had to save up my own money to buy the next one.

### How To: Find the length of a median in a trapezoid

In this tutorial video the author shows how to find the length of the median of a trapezoid. He starts to show that we first need to add the sum of the parallel sides of the trapezoid which are on the either side of the median. Now this obtained value is to be divided by two to get the length of the median. He explains that the length of the median of a trapezoid is nothing but the average of the lengths of the parallel sides of the trapezoid. If you want to learn how to find the length of th...

### How To: Find a missing coordinate given: coordinate & equation

In this video, the instructor shows how to find an unknown coordinate given the other coordinate of that point and the equation that passes thought the point. A point is said to lie on the graph, if the point can satisfy that equation of the line. To check if a particular point satisfies an equation, all you have to do is substitute the value of the point in that equation and check if it validates the equation. Now, substitute the given point with an unknown coordinate in that equation. If th...

### How To: Simplify radicals which are not perfect squares

Need help reducing radical expressions without perfect square or cube roots? Take heart: this free math lesson will ensure that you know everything you need to know for that next big test. Examples include square roots, cube roots, and 4th roots. You'll also learn a technique to simplify n-root expressions as well as how to simplify variables in radical expressions.

### 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: Cancel out in basic algebra

This video gives you brief tutorial on simplifying expressions, or canceling out common factors. He starts out by answering the question "What is canceling?" and demonstrates a basic example. You find the greatest common factor between the numerator and denominator, which you then divide both by. This can also be done if you have variables in your fraction. He then shows it can be done the same way if you have binomials in your fractions. However, you must be careful that the denominator does...

### How To: Subtract a mixed number from a proper fraction in basic math

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. With this free math tutorial, you'll learn how to subtract a mixed number from a fraction in basic arithmetic.

### 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: Find the Height of a Trapezoid.

Step by step directions for finding the height of a trapezoid. Video: .

### 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?

### How To: Convert between pounds and ounces in basic math

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. With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to express ounces as pounds and pounds as ounces.