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# Adding mixed numbers: 19 3/18 + 18 2/3

CCSS.Math:

## Video transcript

let's add 19 and 3:18 to 18 and 2/3 so I like to separate out the whole number of parts from the fraction part so 19 + 3 18 s is the same thing as 19 plus 3 over 18 and to that we are going to add 18 and 2/3 which is the same thing as 18 plus 2/3 now we can separately add the whole number parts so we could add the 19 to the 18 so we could do 19 plus 18 and then we can add the fraction parts plus 3 let me do this in green plus 3 over 18 plus 3 over 18 plus 2/3 plus 2/3 now 19 over 18 pretty straightforward that is what let's see 19 plus 19 would be 38 so there's gonna be one lesson that's going to be 37 so that gives me 37 and then 3 18 plus 2/3 to add them I need to have the same denominator and the least common multiple of 18 + 3 is 18 so let's convert 2/3 to something over 18 so 2/3 2/3 if I want to write it as something over 18 well I multiply the denominator by 6 so I'd also have to multiply the numerator by 6 so it's the same thing as 12 over 18 so I can rewrite 2/3 as 12 over 18 and now I can add these two things together that's going to be so I have 37 + it's gonna be something over 18 plus something over 18 3 plus 12 is 15 plus 15 over 18 and so expressing this as a mixed number I get 37 37 + 15 18 and that's the right number but we can simplify it even more we can simplify the 15 18 so both the numerator and the denominator are divisible by 3 so let's divide them both by 3 and we're not changing the value because we're doing the same thing to the numerator and the denominator and so this gives us we still have our 37 we still have our 37 but the numerator is now 5 and the denominator is now six so we get thirty seven and five six thirty seven and five six and we're done