Hot Education Posts

How To: Build a catapult out of rubber bands & a wire hanger

In this tutorial, we learn how to build a catapult out of rubber bands & a wire hanger. To do this, you will first need: one wire hanger, plastic spoon, rubber bands, small marshmallows, and measuring tape. Now, hold your hand in the center of the hanger and pull up both sides around it. After this, fold back the front for balance and straighten it up so it's stable. Next, you will take one rubber band and put it around the sides. Then, take the spoon and put it in between the rubber band and...

How To: Make polymer putty with household materials

In this tutorial, we learn how to make polymer putty with household materials. You will need: borax, white glue, water, 3 plastic cups and spoons, and food coloring to color your putty. Now, dissolve 4 tbsp of Borax in 2 liters of warm water. Then, prepare equal parts of glue and water together. To make this, you will need 2 parts of the glue solution to 1 part of the Borax solution. Once you mix these together, you can add in some food coloring to it. Pour this into different cups to make di...

How To: Make iron sulfide with sulfur and iron

In this home-science how-to from Household Hacker, we learn how to create an exothermic reaction by combining sulfur with iron, producing iron sulfide in the process. For all of the details, including step-by-step instructions, as well as to see what happens when these two elements meet, watch this video guide.

How To: Properly balance chemical equations

In this video, we learn how to properly balance chemical equations. You will see what substances are in each side of the equation. You will then need to count the atoms that are on each side of the chemical equation. Once you write down the number of atoms on each side, you will need to even them out. To do this, you need to change the coefficients within the equation. These change the total number of atoms inside of a chemical. Once you do this, you will add more to each atom present and the...

How To: Balance chemical equations the right way

In this tutorial, we learn how to balance chemical equations. The first thing you want to do is to draw a graph and label one side reactants and the other side products. Go through each of the atoms that are in your equation on both sides. Write out how many atoms are in each chemical. Then, find a common multiple that will give you and equal amount on each side of the equation. Continue to do this same for all the chemicals in your equation, then when you are finished write it out. Now you w...

How To: Graph & shade a polygon of constraints

This video shows us how to graph & shade a polygon of constraints. Start out by finding the non zero constraints and the other constraints and inequalities. You will need to know how to graph before you begin to do this equation. Look at the first constraint and then fill in the X and Y sign in your table. Continue on to do this for the other two constraints that you have. Once you have these written down and in front of you, it's just a matter of graphing. Start to graph with the given coord...

How To: Change fractions to decimals

In this tutorial, we learn how to change fractions to decimals. Once you learn how to do this, it can help you learn more levels of math. Start out with easy problems and work your way up to more difficult ones. First, try rewriting the equation. Take your top numerator and divide it out by hand by your denominator. After you have done the long math for this, the number that is on the top of the division sign will be your answer. You will need to have a good sense of what numbers add into wha...

How To: Synthesize copper(II) carbonate & sodium bicarbonate

This actions is a video tutorial in the Education category where you are going to learn how to synthesize copper(II) carbonate & sodium bicarbonate. For this you will need copper sulphate which is available in root kill and sodium bicarb which is baking soda. Take 100g of copper sulphate and dissolve in about 400ml of water. Now take 69.27g of baking soda. Add baking soda very slowly and keep stirring the solution. You got to be very careful as the chemical reaction will produce lot of carbon...

How To: Draw an isosceles trapezoid

This is a video tutorial in the Education category where you are going to learn how to draw an isosceles trapezoid. This video demonstrates how to draw an isosceles trapezoid with a long base (B), a short base (b) and a 35 degree angle. First you draw the long base. Now center the short base at the center point of the long base and mark the end points of the short base with dots. Next draw perpendicular dotted lines from the dots extending upwards. Draw 35 degree angles from either end of the...

How To: Use the PRIME operator in math

In this video, we learn how to use the PRIME operator in math. The prime operator is the opposite of something in the equation. Take a look at the illustration in the video that is shown. Once you see that, you will be able to tell what A prime and B prime are. A prime is the opposite of "A". If a number is shaded in "A" it should not be shaded in "A Prime". The same goes for the prime of the letter "B". Just pay attention to what the numbers selected for each letter is, then use the opposite...

How To: Make your own nylon

In this tutorial, we learn how to make your own nylon. You will need: pipettes, pipette filler, forceps, beaker, stir rod, sebacoyl chloride and hexanediame solution. Now, pour some of the hexanediame solution into the small beaker. Add in a food coloring if you want to make this a specific color. After this, add in 4 cc's of sebacoyl chloride and carefully drip into the side of the beaker. You should see a layer of where the two liquids are after this. Now, take your tweezers and reach into ...

How To: Make a light bulb from a pickle

In this Education video tutorial you will learn how to make a light bulb from a pickle. Pickles are high in ions in the form of acids and salts. These are electrolytes and they will transfer energy through the pickle. Place a pickle on a glass plate and hook it up with an AC power cord with a nail on each end as shown in the video. You must have protective gloves on. Poke the nails on each end of the pickle and hook up the cord to the power source. The pickle will start emitting light which i...

How To: Find how many toothpicks will be needed to form the nth figure in a sequence

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 employ inductive reasoning to determine the number of toothpicks you'll require to generate the nth (e.g., the 50th) figure in a sequence of figures.

How To: Make a dye-sensitized solar cell with titanium dioxide and anthocyanin

Discover the power of raspberries! Literally. In this NurdRage science video, learn how some crushed raspberries and some titanium dioxide (TiO2) can create a powered dye-sensitized solar cell. Inside a raspberry is something called anthocyanin, which is a flavonoid pigment. Commercially purchased solar cells are way more powerful than this DIY solar cell, but with a little improvement, who knows. Nurd Rage also lets you know how this works.

How To: Calculate the width of a fence given its length and perimeter

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 find the width of a fence when given numbers for its length and perimeter.

How To: Convert decimeters to kilometers 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 convert between decimeters and kilometers in basic mathematics.

How To: Get a coin out of water without getting wet

In this tutorial, we learn how to get a coin out of water without getting wet. First, place the coin inside of water on a plate. Next, use a lighter to light a piece of paper on fire, then place the paper inside the water cup and let it smoke and burn. Next, push the cup down onto the plate, and it will soak up all the water that was on the plate! Then, your penny will be dry and you can pick it up without getting wet! This is a great trick to show your friends and works easily without any pr...

How To: Make glow sticks with DEP, TCPO, sodium acetate & dye

If you prefer glow sticks over candles during a power outage, then this how-to is for you! Although glow sticks are used as temporary light sources, there are other applications for them. Divers use them for night diving, fisherman use them to catch swordfish, and the military uses them for light markers, along with infrared versions used in conjunction with night vision devices. But with all these handy uses for glow sticks, the most popular is — recreational use, like dancing at raves, some...

How To: "Back out the tax" from a receipt

In this video, we learn how to back out the tax from a receipt. If you have a receipt where you see how much you paid and know the tax rate, except you want to figure out the cost of the item before the tax. First, take the cost of the item including tax and what the tax rate is. To figure out the original price, let x equal the cost of the item. Add the tax to the cost of the item which will equal the cost you paid. Perform the equation 1x+(tax rate)= (total price). After you figure this equ...

How To: Write an introduction to your academic essay

In this tutorial, we learn how to write an introduction to your academic essay. The first part of your introduction should say why the topic is important. Using the phrase "is a topic of growing importance" is a great way to help boost your topic's importance. Next, you should have a sentence or two sentences talking about the difficulties of the topic and what issues are involved. The third part of your introduction should be a thesis statement that narrows down what the topic is going to be...

How To: Know if matrices can be multiplied

In this Education video tutorial you will learn how to know if matrices can be multiplied. If the column of the first and the row of the second match, you can multiply them. For example if, matrix A has 2 rows and 3 columns (A: 2x3) and matrix B has 3 rows and 4 columns (B: 3x4), then you can multiply them. But, if A: 3x2 and B: 3x4, you cannot multiply them. The shape of the resultant matrix will be the shape of the outer numbers. For example, we saw that if A:2x3 and B :3x2, then they can b...

How To: Find the equation for a growth pattern

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). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to find an equation that describse the growth pattern of a sequence of blocks.

How To: Simplify a radical expression including variables

Want to simplify a radical expression with algebraic variables? See how it's done with this free video algebra 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 study for that next big test).

How To: Use radical notation to evaluate rational exponents

Learn how to evaluate rational exponents using radical notation in this free video algebra 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 study for that next big test).

How To: Factor polynomials in algebra using the GCF method

Need to know how to factor polynomials using the GCF method? Learn how with this free video algebra 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 study for that next big test).

How To: Factor trinomials by grouping in algebra

Learn how to factor trinomials using the grouping method in this free video algebra 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 study for that next big test).

How To: Solve a word problem for the perimeter of a rectangle

Need a little bit of help figuring out how to solve word problems involving the perimeter of a rectangle? See how it's done with this free video math 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: Apply the Pythagorean theorem

Meet the Pythagorean theorem—an indispensable tool for any budding geometer. The Pythagorean theorem will allow you to measure the hypotenuse or any other side of a right triangle when the length of its other two sides are known. For specific, step-by-step instructions on how to use this useful formula, usually given as a^2+b^2=c^2, where c^2 is equal to the length of the hypotenuse, watch this free video geometry lesson.

How To: Find the inverse of a function in algebra

Need a little help figuring out how to find the inverse of a function in algebra? Watch 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). With this free math tutorial, you'll learn how to calculate the inverse of a given algebraic fun...

How To: Clear decimals from a linear equation

Need instructions on how to remove decimal values from a linear equation in algebra? 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: Graph an inequality in slope-intercept form

This how to video shows you how to graph an inequality in slope intercept form. First, graph the line. Depending on the inequality, use a dash or solid line. Use a solid line for less than or equal to or greater than or equal to. Use a dash line for greater than or less than. If y is less than or less than or equal to, shade the bottom area of the line. If it is y is greater than or greater than or equal to, shade the top area of the line. Check your answer by substituting in any point from t...

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...