Pre-Algebra Tutorial

Pre-Algebra Equations x + 3 = 5 What is the value of x? At first glance this may look easy since all you have to ask yourself is What plus three is equal to 5? But the proper way to solve this problem algebraically is as follows:

Pre-Algebra We want to leave x on the left side by itself and then the answer will be on the right side. So to do this, we subtract 3 from both sides… x + 3 = x = 2

Pre-Algebra Now let’s check our work: = 5 TRUE!!

Pre-Algebra Now lets try to add some multiplication to the equation: 2x + 3 = 15 Again, we are solving for x First we must do the same thing as above. We want to get rid of all the numbers on the left side and just be left with x.

Pre-Algebra So again, we subtract 3 from both sides to get rid of the 3 2x + 3 = x = 12

Pre-Algebra Now we still have an equation to solve and we still need to get x by itself. So how do we isolate x? Well, if we divide both sides by 2, we should have our answer. 2x = 12 2

Pre-Algebra This can also be written as: 2x 2 = 12 2 So…. x = 6

Pre-Algebra Fractions A lot of people are intimidated by fractions, but if you just take it one step at a time and remember a few simple rules, you’ll be cruising through these in no time! The top is called the numerator and the bottom number is called the denominator. The denominator must always be the same in addition and subtraction.

Pre-Algebra Lets try a few… Since the denominators – or the bottom numbers are the same, all we have to do is add the numerators together. So our answer is 3 4

Pre-Algebra But what if the denominator is different? Things just got a little more complicated. Now we have to make the denominators the same. So the easiest way to do this is to place the fractions on top of each other and solve across and down like this….

Pre-Algebra We need to find the common denominator for 2 and 3. So what number is divisible by both. Can you divide 4 by 2? Yes. Can you divide 4 by 3? No…How about 5? No to both? How about 6? YES!

Pre-Algebra So we write that like this… 1 ? ? 2 6 Now we need to calculate the numerator. Remember, whatever you do to one side, you have to do to the other. In this case, whatever we do to the bottom, we must do also to the top.

Pre-Algebra How do we get 6 for the denominator? Well, 3 x 2 = 6 …and likewise, 2 x 3 = 6 Now let’s do the same to the top. See below…. 1 (x2)= 2 3 (x2)= 6 1 (x3)= 3 2 (x3)= 6

Pre-Algebra Now we are ready to add our new fractions together since they have the same denominator And there you have it!

Pre-Algebra Fractions, Decimals, & Percentages Many of us are accustomed to decimals since we add dollars and cents on a daily basis. But do you know how convert a fraction to a decimal? Or how to convert a fraction to a percent? Trust me, it’s easier than it sounds…

Pre-Algebra To convert a fraction to a decimal, just divide the numerator by the denominator like this…. 1 4 would be… 1 4 Now don’t go running for your calculator, let’s do this the old fashioned way…

Pre-Algebra

So… Now let’s try converting that to a percent. To convert a decimal to a percent, just move the decimal two places to the right!! So… = 25% Simple enough, right?

Pre-Algebra But what if we wanted to take a fraction and convert it to a percent? Well, if you look at the steps above, we’ve already done that. Just divide the numerator by the denominator and move the decimal two places to the right! Voila! Now you are a math whiz and ready to move on to the test for this module. Good luck!

Pre-Algebra You must make a perfect score of 100% to pass. Click here to take the test for this module.