# Hot Education Posts

### How To: Find a slope of a straight line with: Ax + By + C = 0

In this video the instructor shows how to find the slope of an equation which is in the form Ax + By + C = 0. He says that the formula to find the slope of a line in the above form is slope m = -A/B, where A and B are the numeric constants of the variables x and y in the given equation. He goes on and further shows how to do this with a couple of examples. He shows how to reduce any equation into the general form and how to apply the slope formula then. This video shows how to find the slope ...

### 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 a Monster Dry Ice Bubble

Sure it's been done before, but it never gets old. There's something magical about dry ice, bubbles, and especially the result you see when they're combined!

### 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: 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: 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: 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: Identify characteristics of a sample during a survey

To identify characteristics of a sample in your survey, there are many factors to consider of your samples. The first four characteristics you need to focus on are gender, age, income level, and education level. All four of these characteristics must be proportional to that of the population. You also need to consider the geographic location. Only take samples from the immediate geographical area. Finally, an important characteristic of the survey is the sample size. You do not want to ask to...

### 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: Solve percentages without a calculator

Want to know how to find percentages quickly without the use of a calculator? It's easy. This free video math lesson will show you how it's done. 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: 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: Find the 100th term in a sequence

Need to find the nth term in a given arithmetic sequence? See how it's done with this free video math lesson. Need help finding the 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 seri...

### 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: 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: 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: Perform separation by decantation in the chemistry lab

Find out how everything in a chemistry lab works, from pipettes to burners to recrystallization to storage. You'll get precise instructions on how to work and perform certain scientific duties in the chem lab, whether it's chemical or just ordinary high school science.

### Classic Chemistry: Colorize Colorless Liquids with "Black" Magic, AKA the Iodine Clock Reaction

Want to make boring old colorless water brighten up on command? Well, you can control the color of water with this little magic trick. Actually, it's not really magic, but a classic science experiment known commonly as the iodine clock reaction, which uses the reactions between water and chemicals to instantly colorize water, seemingly by command. You can use different colorless chemicals to produce different colors, and you can even make the color vanish to make the water clear again.

### 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: 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: 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: Turn water into ice without a freezer

Here's a fun experiment you can do that will demonstrate the effects that pressure has on the freezing point of a liquid. You will amaze your friends as you do what seems to be impossible, turning water into ice without sticking it in the freezer.

### How To: Find points of intersection in different equations

In this tutorial the instructor shows how to solve linear and quadratic equations. It is a liner quadratic system where he shows a parabola and a straight line and he intends to solve the points where the line intersects the parabola. Now he uses comparison to compare the values of y in both the equation resulting in a equation in x. Now he shows the factors of the obtained polynomial equation and there by finding the values of x coordinates. Now he substitutes these values of x in the origin...

### 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: Evaluate logarithms using a calculator TI-83

A video to help calculator users find the natural logarithm (log base e, or "ln") and standard logarithm (log base 10, or simply "log") of any number using a TI-83 calculator (works for any issue of the TI-83 calculator or even a TI-84 calculator). Turn on your calculator. To find the natural log of a number, press the "ln" button (the third button from the bottom left), enter the number you want to find the natural log of, press the ")" (closed parenthesis) button, then press enter. The same...

### How To: Complete a proof involving segments

This video from Yay Math! is a geometry lesson on how to complete a proof involving segments. He draws a line segment with four points labeled A, B, C and D. The problem is as follows: Given: AC is equivalent to BD. Prove that AB is equivalent to CD. The first statement of proof is the given. Next, you need to define the congruent segments and state that they're equal in measurement. Next, break down the segments: AC=AB+BC, and BD=BC+CD. This is called segment addition postulate. The end of t...

### How To: Use and find x & y-intercepts in algebra

A straight line can be represented in the form of a liner equation containing two variables x and y. When the equation is graphed on a pair of coordinate axes, the line passes cut through the axes in two points. The point where the line cuts the x-axes is called as its x coordinate and the point where the line cuts the y-axes is called as its y coordinate. In this way a line has x-intercept and y-intercept. The x-intercept of a line lies on x axes and is in the form (a,0). Similarly the y-int...

### How To: Create a plankton science model

In this tutorial, we learn how to create a plankton science model. You will first need a clear bucket with water, modeling clay, toothpicks, sponge, beads, buttons, pipe cleaners, Styrofoam peanuts, and more. To make the plankton, you will first take the peanut and stick a toothpick into it. Then, add a paperclip on top of that to give it some weight. Drop it into the water and see if it floats or sinks. Add some more weight to it to see how much weight it takes to sink it to the bottom. Have...

### How To: Do a simple experiment using copper wire and battery

In this video Mr.G puts a new spin on magnets and bare copper wire with just a simple battery. Motion via magic? Not quite, but pretty darn close! Join Mr. G, and build your own motor with its own unique new spin. This is a fun, easy, do it at home experiment.

### How To: Make copper hydroxide Cu(OH)2 with copper metal

In this home-science how-to, we learn how to synthesize copper hydroxide Cu(OH)2 using copper metal and the electro-chemical approach. For detailed, step-by-step instructions, and to get started making your own copper hydroxide, watch this video guide form YouTube user sciencoking.

### 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: Use the TOA formula in trigonometry

The video is a tutorial in trigonometry. The teacher teaches that the tangent or the tan of an angle is the ratio of the opposite side to the adjacent side of a right angled triangle. If one side and one angle is given then the value of the unknown side can be found by solving the equation tan of angle is equal to opposite upon adjacent side. If the angle is to be found then the tan inverse of the value is seen in the calculator.

### 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: Evaluate a line integral along a straight line segment

This video tutorial is in the Education category which will show you how to evaluate a line integral along a straight line segment using the definition of the line integral. This video evaluates a line integral along a straight line segment using a parametric representation of the curve (using a vector representation of the line segment) and then integrating. A vector representation of a line that starts at r0 and ends at r1 is r(t) = (1-t)r0 + tr1 where t is greater than equal to 0 and lesse...

### How To: Stiffen water with flour and salt

See what happens when you mix a few cooking ingredients into water! This video tutorial will show you the trick to stiffen water with flour and salt. It's a pretty simple trick, and you don't need to be a science genius to do it. Just mix a little salt and flour together, then dump into the pre-boiled water and watch as it hardens completely stiff.

### How To: Solve algebraic equations with the y = mx+b format

This video shows us how to solve algebraic equations with the y = mx+b format. When talking about solving y=mx+b format, it’s about solving linear equations so that y is on one side and with some terms x on the other side. Here in this equation 'm' is actually the slope of the line and slope= (rise/run) and it is interrupted with the term 'b'. This can be explained by taking an example of the same format. In the example 2x+3y=9, we need to shift the term '2x' to the other side so that the equ...

### How To: Make a never ending foam snake

In this video the author shows how to make a never ending foam snake. He starts by speaking about how hydrogen peroxide can be fun. He starts with the requirements first which are a dish soap, a bottle of hydrogen peroxide, some dry yeast, and a red fruit color. Now he fills up a cup with hydrogen peroxide, adds the color and two table spoons of dish soap. Now he shows how to use yeast which is used to remove the oxygen from the hydrogen peroxide. And finally he demonstrates the never ending ...

### How To: Make liquid sculptures from a handwarmer

Learn how to make liquid sculptures from a hand warmer in simple steps. First buy an instant reusable hand warmer which has sodium acetate in it and keep it ready. Now use 4 packets of the hand warmer and stir them out with water. Transfer them to a bottle and keep it aside. Take a sodium acetate crystal from a used hand warmer and place it in a plate. Now pour the liquid slowly on the crystal and you can see the liquid turns solid as you pour it. Design your masterpiece using all the liquid....

### How To: Light an energy saving bulb without plugging it

This video shows the viewer how to light an energy saving light bulb without plugging it in. The process is also explained in detail during the video. To light the bulb you need to inflate a standard balloon. Then rub the balloon over either a fabric or your hair. Then move the balloon back and forth near the light bulb. The bulb should glow dimly. This effect occurs because the balloon is negatively charged. This means that it has more electrons than protons. The video then goes on to explai...

### How To: Solve multi-step and compound inequalities

Multi-Step inequalities are inequalities which take more than one step in solving them. You need to follow a step by step approach in solving these kind of problems. Through there is no general method to solve them you can follow a set of guidelines. First thing you have to do is make sure that only x terms remain on the left hand side of the equation. If there are any other numerical terms add the negative of that term to both the sides of the equation to eliminate it on the left hand side. ...

### How To: Calculate the age of the universe w/ Hubble's constant

This is a great instructional video on how to calculate the age of Universe from Hubble's constant. The speed the galaxy moves away from us is directly proportional to the distance from us. Now think of big bang theory. Hubble's constant is equal to velocity over distance. 1 over Hubble's constant is equal to distance over velocity that is equal to time. Time equals to 1over 71. If you change it into all the same units words it is one over 71000 or 3.09x 10 to the power of 22. It is 3.09x10 t...