Home / Questions / WHAT IS THE NUMBER 3.142 MORE USUALLY KNOWN AS? PI (PRONOUNCED ‘PIE’ – IT REPRESENTS THE RATIO OF A CIRCLE’S CIRCUMFERANCE TO ITS DIAMETER, ALSO EXPRESSED BY THE FRACTION 22/7, AND THE SIXTEENTH LETTER OF THE GREEK ALPHABET, PI, EQUATING TO ‘P’, AND SHOWN AS THE SYMBOL P . THE NUMBER 3.142 IS A ROUNDING TO THREE DECIMAL PLACES; THE FULL DECIMAL NUMBER OF PI IS INFINITELY LONG AND CANNOT BE EXPRESSED ABSOLUTELY OTHER THAN AS A FRACTION.?