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What is the easiest method for adding and subtracting rational numbers
You need to be more specific. Do you mean rational numbers represented as fractions, like ##\frac{1}{2} + \frac{3}{5}## or rational numbers represented as decimal fractions, like .5 + .6?What is the easiest method for adding and subtracting rational numbers
What is the easiest method for adding and subtracting rational numbers
To elaborate on what AMenendez is saying, we are multiplying each fraction by 1 in some form so as to get the denominator we want.So, the standard way of adding / subtracting numbers is to first identify a ``least common denominator". So, say I had:
##\frac{1}{2} + \frac{3}{7}##
Well, what is the smallest number that is a multiple of both 2 and 7? It's 14. So now, how do we write the original fractions with denominators of 14? Well, we multiply 2 by 7 to get 14, so we do the same to the numberator, 1. Likewise, we multiply 7 by 2 to get 14, so we multiply 3 by 2 to get 6. So we may write
##\frac{1}{2} + \frac{3}{7} = \frac{7}{14} + \frac{6}{14} = \frac{13}{14}##
AMenendez said:Which doesn't reduce. So, very roughly speaking,
##\frac{a}{bc} + \frac{d}{ef} = \frac{(aef)+(bcd)}{bcef}##