Pi is an irrational number
It is a non non-terminating, non-recurring decimal. It is an irrational number.
5/6 written as a recurring decimal is 0.83333...
7/9 written as a recurring decimal is 0.7777 repeating
Decimals can be "terminating" "recurring" or "other." A terminating decimal is one which is finite. Recurring and other decimals continue on forever. For instance 0.5 is a terminating decimal. 0.729 is a terminating decimal. 0.3333333... is not a terminating decimal. pi (3.1415926535....) is not a terminating decimal.
No.
It is a decimal fraction: for example 0.25 or 0.166... recurring
It is a finite decimal (i.e. one that is not infinitely recurring. Thus pi, e and root 2 are not terminating decimals).
Not all decimals can be expressed as fractions. Only terminating and recurring decimals can be expressed as fractions. eg a recurring decimal: 0.3333333... = 1/3 A terminating decimal: 0.125 = 1/8 A decimal that does not recurr or terminate, cannot be expressed as a fraction. eg Pi = 3.141592654... Pi can not be expressed as a fraction as it does not recurr or terminate. It can only be approximated to a fraction. eg Pi ≈ 355/113 but is correct to 6 decimal places.
Terminating or recurring.
pi is a transcendental number, which is a kind of irrational number. That means that the decimal representation of pi does not end (nor does it have a recurring sequence). There is, therefore, no last digit.
All numbers are unique and so there is no other number equal to pi. Pi is not a rational number so there is no fraction that is equal to pi. It has an infinitely long non-recurring decimal representation so there is no way to write a decimal eqiuvalent either.