### Video instructions and help with filling out and completing How Form 8815 Subtract

### Instructions and Help about How Form 8815 Subtract

One of the trickiest things to pick up on is how to work with fraction the reaction most people have when they see a fraction is to run the other direction fractions fractions and that's not what we want to do what we want to do is hit them right on the head we need to add we need to subtract fractions we need to multiply and divide the four basic operations that's all we have to do first we have to learn to add them which is actually the hardest one for me okay so we want to add 2/5 plus 1/5 we need to have a rule or some sort of process to add a fraction Curtis do you know how to add fractions I sure can mister mangled or hi I'm Curtis and n fractions is easy to fence plus 1/5 2 plus 1 is 1 2 3 & 6 this bottom number is the same I just keep it 2/5 plus 1/5 I reckon is gonna be 3/5 okay thanks Curtis as he said if the bottom numbers are the same then we can just add the top two numbers that's it if the bottom numbers are the same if they have a common denominator we add the top two numbers and keep the original bottom number so what happens when we have a different denominator or the number on the bottom is not the same how do we add the top numbers right there's gotta be something for that Curtis do you know you know I - sure how to because those bottom numbers is their friend okay maybe not so when looking this is really easy we want to make this bottom number the same so we can follow our first rule and just add the top two numbers the easiest thing to do is multiply each number by the other number so I can see that 2 times 3 equals 6 so my answer is going to be out of 6 I see that so really I want to rewrite these with the base number of 6 so this one needs to be multiplied by 3 and if I do it to the bottom I need to do it to the top if I do it to the bottom one then to do to the top I'm going to rewrite this one has 3 over 6 what do you think I multiply this one by this one right - I'm going to do it to the top and the bottom and I get 6 and 2 easy enough right and now we just add straight across any guesses well let's see got my minecraft uh blind box here I figured I could just open this up and see what uh see what's inside see if I got a minifigure I don't know I don't know let's see five six it's the answer subtracting fractions is pretty easy especially when we have the same denominator or they're over the same number this bottom number being five means that we can just subtract the top numbers for addition and subtraction we just need the bottom numbers to be the same Curtis can you get this one hi I'm Curtis and subtracting fractions is easy if we look here we see that this bottom number is in fact the same this five is the same as this size on top I see a 2 and a 1 and a subtraction sign so if then bottom numbers is the same we just subtract the top ones and keep the bottom number and I know that to take away one leaves me with one two-fifths subtracting one fifth is gonna equal one fifth if we're gonna subtract fractions and they have a different denominator on the bottom just like when we add fractions we must find the common denominator the easiest way to do that is to multiply these two numbers together which tells me that my answer can be over six I can always reduce at the end but the easiest thing to do is multiply those together and then know that I want to rewrite these two fractions as being out of six so this one must be written times three on both the top and the bottom here I'm gonna multiply by two 3 minus 2 is 1 over 6 it's very simple just remember with fractions if you multiply them by each other on the bottom you'll get a common denominator and you can always reduce at the end always take time to rewrite the problem to make it in a format that you understand and looks a little more clear to you once we have adding and subtracting fractions down we're gonna look at multiplying them it's actually my favorite because it's the easiest it's all easy but multiplying is the easiest all we do is multiply straight across it's like 2 multiplication problems that results in a fraction so let's go ahead and do this one 1 times 3 is 3 2 times 4 is 8 that's it when you're multiplying fractions straight across every time multiplying fractions no problem you just do it straight across to multiplication problems 2 times 3 and 5 times 5 and you get a resulting fraction Kurtis does this make sense is it a peanut ok well let's go ahead and move on here 2 times 3 is 6 and 5 times 5 is 25 it's that simple multiplying is the easiest thing to do with fractions dividing fractions is almost as easy as multiplying then multiplying we just do it straight across dividing we have one more step we have to flip this second fraction it's called a reciprocal that's just this number flipped over so the recipie of 3/4 is 4/3 that's right and then we keep our first one the same and now we multiply and if you remember we just multiply.