Methods aren't necessary. The only common factor (which makes it the GCF) of 16 and 35 is 1.
To answer GCF and LCM questions.
They do not necessarily use them every day.
It doesn't matter what method you use, you need at least two numbers to find a GCF.
Prime numbers help you to find the LCM and the GCF.
2 x 3 = 6 2 x 5 = 10 The GCF is 2.
Gcf you use when you are finding the greatest factor for the numbers. Lcm you use when you are finding the smallest multiple in the numbers factors
you use the lcm (least common multiple).
To find the GCF and the LCM you have to first at least try to use prime factorization. So use factor trees. Or for the LCM find th least common multiples of the number.
To answer GCF and LCM questions.
Use the GCF to reduce fractions. Use the LCM to add and subtract unlike fractions. Carpenters work with fractions a lot.
The GCF of 50 and 54 is 2. Use whatever method you wish.
If you use methods based on prime factors, it is the same whether you have 2, 3, or more numbers: find all the factors that occur in any of your numbers. If you use a method based on Euclid's Algorithm (that is, lcm(a, b) = a x b / gcf(a, b), where you find the gcf with Euclid's Algorithm), then you can find the lcm for two numbers at a time. For example, to get the lcm of four numbers, find the lcm of the first two, then the lcm of the result and the third number, than the lcm of the result and the fourth number.
Finding the LCM will make adding and subtracting fractions easier.
They do not necessarily use them every day.
No matter what method you use, you need at least two numbers to find an LCM.
It doesn't matter what method you use, you need at least two numbers to find a GCF.
To find the GCF of 9x^2y and 39xy^3 first look at the GCF of 9 and 39 with is 3 Now the GCF of x^2 and x is x and the GCF of y^3 and y is y so the GCF of the 9x^2y and 39xy^3 is 3xy Use a similar idea to find the LCM. The LCM of x^2 and x is x^2 and the LCM of y^3 and y is y^3, lastly, the LCM of 9 and 39 is 117 so the LCM is 117x^2y^3