Question

When adding fractions, and you have to find the lowest common denominator. How do you know when to change the numerator? I am really confused!!!!

Answer 1

Example: 1/2 + 1/6, to change the 2 in the denominator of the first, you just multiply by a 3 and whatever you do to the denominator, you do to the numerator, so you get: (1*3)/(2*3) gives you 3/6+1/6=4/6 which if you simplify comes out to 2/3.