<P> In India, the day' December 22 has been declared as the National Mathematics Day . The Declaration was made by Dr Manmohan Singh, Former Prime Minister of India, during the inaugural ceremony of the celebrations to mark the 125th birth anniversary of Srinivasa Ramanujan held at the Madras University Centenary Auditorium on 26 February 2012 . Dr Manmohan Singh also announced that the year 2012 would be celebrated as the National Mathematics Year . </P> <P> The Indian mathematical genius Srinivasa Ramanujan was born on 22 December 1887 and died on 26 April 1920 . It was in recognition of his contribution to mathematics the Government of India decided to celebrate Ramanujan's birthday as the National Mathematics Day every year and to celebrate 2012 as the National_Mathematics_Year . National Mathematics Day is celebrated with numerous educational events held at Indian schools and universities . </P>

Whose birthday anniversary celebrated as national mathematics day