Adding Fractions with Unlike Denominators (Part 2) | Math with Mr. J

[Music] welcome to math with mr j [Music] in this video i'm going to cover how to add fractions with unlike denominators and this is part two so if you need part one that link is down in the description if you're ready for part two let's jump into number one where we have three sevenths plus five fourteenths and the first thing that we need to do is find a common denominator now like i mentioned in part one you may recognize what that common denominator is right when you see the problem but if not you can always write out your lists of multiples in order to find it so let's write out some multiples of both 7 and 14 and see if we have any common multiples specifically the least common multiple so we'll start with seven so 7 14 21 28. let's do 14 so 14 here and the first multiple of 14 is 14 and we have a common multiple specifically the least common multiple so 14 is going to be our common denominator let's go back up to our original problem and rename both of these fractions with that common denominator of 14. we'll start with 3 7 so we need to find an equivalent fraction to 3 7 with a denominator of 14. so think how do we get 7 to equal 14 well we know 7 times 2 is 14 and in order to keep this equivalent whatever we do to the denominator we do to the numerator so let's multiply the numerator by 2 as well 3 times two is six now we do five fourteenths well five fourteenths already has a denominator of fourteen so we don't need to rename so we can bring that five down now we're ready to add so add the numerators 6 plus 5 is 11. keep our denominator the same so 11 14 is our final answer look to see if we can simplify 11 14 is in simplest form the only common factor between 11 and 14 is one so we are done let's try another one and move on to number two where we have two eighths plus six twelfths first thing that we need to do find a common denominator so let's write out our multiples for eight and twelve we'll start with eight so 8 16 24 32. let's do 12 now 12 24 and it looks like we have a common multiple a least common multiple of 24 so 24 is going to be our common denominator let's rename these fractions with that common denominator and we'll start with 2 8 so let's think how do we get 8 to equal 24 8 times what equals 24 well 8 times 3 is 24 so we need to do the same thing to the numerator in order to keep this equivalent so two times three equals six so six twenty fourths is equivalent to two eighths now let's do six twelfths well we know 12 times 2 is 24 let's do that same thing to the numerator to keep this equivalent 6 times 2 is 12. so now we have our renamed fractions with that common denominator of 24 so we can add 6 plus 12 is 18. keep the denominator of 24 in our answer so we get eighteen twenty fourths now that is the correct answer but it can be simplified we can break that down into its lowest terms so we need to look for common factors between eighteen and twenty four there are multiple paths in order to get to the simplified answer here but if you pick the greatest common factor between 18 and 24 you can do it in one step so the greatest common factor between 18 and 24 is 6 so let's divide both by 6 in order to get the simplified answer so 18 divided by 6 and 24 divided by 6. 18 divided by 6 is 3 and 24 divided by 6 is 4 so 3 4 is the simplified answer but i do want to make this clear 18 24 is the correct answer but we simplified to three-fourths if you need a little more help or clarification on simplifying i added a link to my video on simplifying fractions down in the description so there you have it there's how you add fractions with unlike denominators i hope that helped thanks so much for watching until next time peace