Fraction | Function to return gcd of a and b ; Function to convert the obtained fraction into it 's simplest form ; Finding gcd of both terms ; Converting both terms into simpler terms by dividing them by common factor ; Function to add two fractions ; Finding gcd of den1 and den2 ; Denominator of final fraction obtained finding LCM of den1 and den2 LCM * GCD = a * b ; Changing the fractions to have same denominator Numerator of the final fraction obtained ; Calling function to convert final fraction into it 's  simplest form ; Driver Code
< ? php function gcd ( $ a , $ b ) { if ( $ a == 0 ) return $ b ; return gcd ( $ b % $ a , $ a ) ; } function lowest ( & $ den3 , & $ num3 ) { $ common_factor = gcd ( $ num3 , $ den3 ) ; $ den3 = ( int ) $ den3 / $ common_factor ; $ num3 = ( int ) $ num3 / $ common_factor ; } function addFraction ( $ num1 , $ den1 , $ num2 , $ den2 , & $ num3 , & $ den3 ) { $ den3 = gcd ( $ den1 , $ den2 ) ; $ den3 = ( $ den1 * $ den2 ) / $ den3 ; $ num3 = ( $ num1 ) * ( $ den3 / $ den1 ) + ( $ num2 ) * ( $ den3 / $ den2 ) ; lowest ( $ den3 , $ num3 ) ; } $ num1 = 1 ; $ den1 = 500 ; $ num2 = 2 ; $ den2 = 1500 ; $ den3 ; $ num3 ; addFraction ( $ num1 , $ den1 , $ num2 , $ den2 , $ num3 , $ den3 ) ; echo $ num1 , " / " , $ den1 , " ▁ + ▁ " , $ num2 , " / " , $ den2 , " ▁ is ▁ equal ▁ to ▁ " , $ num3 , " / " , $ den3 , " STRNEWLINE " ; ? >