



 
Hi Peter. A fraction is a ratio of finite integers. Whenever you have a ratio of integers, the corresponding decimal value either terminates or repeats in no more digits than the size of the denominator. For example, 3/7 Thus if a decimal NEVER repeats and NEVER terminates, it cannot be represented as a ratio of two integers. So we call such number irrational (not a ratio). An example of this is the number π. The decimal equivalent of π never repeats and never terminates (here's a link to the first 70 billion digits). Other common examples are any square root except for roots of perfect squares and the number φ which is the Golden Ratio. Cheers,  


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