Do you really have to draw a factor tree and work with primes every time you encounter adding or subtracting fractions?
Not this way - LCM(8,15)...
15: 15, 30, 45, 50, 65, *80* -- 8: 8, 16, 24, 32, 40, 48, 56, 64, 72, *80* --
This makes adding and subtracting fractions quite a lot of work.
What is the most efficient and effective practice in regards to dealing with adding or subtracting fractions? Is there a faster way to add or subtract fractions? I heard of the "Butterfly Method" but it involves a lot of rules. The factor tree seemed easier. I came here to see if determining the least common denominator of two fractions can be done even more efficiently.