welcome to math with mr. J in this video I'm going to be doing a fraction review so a quick refresher on adding subtracting multiplying and dividing fractions if you're looking for more of an in-depth explanation I drop the links to those videos below in the description but if you're just looking to brush up on your skills or a quick reminder on how to add subtract multiply and divide fractions then this is the video for you so let's jump right in the number one here where we have addition 5/8 plus 1/3 now with adding fractions we cannot just start adding straight across we need to make sure we have a common denominator first so our denominators are an 8 and a 3 so the common denominator for fractions will be whatever the least common multiple is and the least common multiple for 8 & 3 is 24 so I'm going to rewrite these fractions below with a denominator of 24 so what we need to do now is rename them using equivalent fractions so they both have a denominator of 24 so I know 8 times 3 gives me 24 so in order to get an equivalent fraction I need to do the same thing to the top so 5 times 3 is 15 so 5/8 is equivalent to 15 twenty-fourths now for 1/3 3 times 8 gives me that 24 so I need to do the same thing to the top 1 times 8 is 8 so now that I have the renamed fractions with a denominator of 24 I can add my numerators 15 plus 8 is 23 and you always keep your denominator the same whatever that common denominator is which it is 24 then check to see if your answer can be simplified if there's a common factor that I can divide both my numerator and denominator by well the only common factor is one here so we are in simplest form our answers 23 24 so number 2 on to subtraction and subtraction is the same exact thing as addition you just subtract instead of add so we have 1/2 minus 2/5 we obviously don't have a common denominator there so we are not able to subtract right off the bat so we need to find a common denominator which again is going to be your least common multiple so 2 & 5 our least common multiple is going to be 10 I know 2 times 5 is 10 1 times 5 is 5 so 1/2 is equivalent to 5/10 now on to 2/5 here 5 times 2 gives me that denominator of 10 so 2 times 2 gives me 4 now I'm ready to subtract 5 minus 4 is 1 and we keep our denominator of 10 the same so 1/10 is our answer now you always look to simplify just like number one there but our only common factor between 1 and 10 is 1 so we are in simplest form number 3 multiplying fractions so with multiplying fractions we do not need a common denominator you actually just multiply straight across so you go numerator times numerator and denominator times denominator so 2 times 1 is 2 and 8 times 4 is 32 so that's our answer now this fraction can be simplified there's a common factor between 2 and 30 - so we can break this fraction down the common factor between two and 32 is 2 so I can divide both of them by 2 and I will get the equivalent fraction which is our simplest form of 2 over 32 which 2 divided by 2 is 1 and 32 divided by 2 is 16 so our simplest form answer here is 1/16 number 4 5/6 divided by 2/7 now for dividing fractions we keep switch and flip so whatever our first fraction is we always keep it we switch the division sign to multiplication and we flip the second fraction so the 7 is going to be our numerator and the 2 is going to be the denominator keep switch flip 5 times 7 is 35 and 6 times 2 is 12 this gives us an improper fraction and we don't want to leave it like that we want to convert this to a mixed number so essentially it's 35 divided by 12 how many whole twelfths can we pull out of 35 and that's going to be our whole number and so if we think about if we count up by 12 12 24 36 so three twelfths is a little bit too much so it's only going to be two whole twelfths which gets us to 24 that means we have 11 left over as our remainder and we keep our denominator of 12 the same so again I did 35 divided by 12 two whole twelves can be pulled out of 35 with 11 left over and you keep your denominator of 12 the same and eleven-twelfths cannot be simplified so we are done with number four so there you have it there's adding subtracting multiplying and dividing fractions again this was meant to be a review so if you need more examples or more in-depth instruction I drop the links to those videos below in the description thanks so much for watching until next time peace you