South Africa\'s 12 million schoolchildren sang happy birthday to Nelson Mandela as he turned 94 on Wednesday, at the start of events to honour the country\'s first black president. At 8:00 am (0600 GMT), children began their day at school with a special birthday song ringing with the line: \"We love you father\". \"This is a very important day for all of us,\" said Paul Ramela, principal at a primary school in Soweto. \"We are here to celebrate the birthday of a very important person, a person who has liberated us from apartheid,\" he told his students. \"Mandela spent 67 years of his life to improve the lives of other people. He has done so much for all of us.\" Mandela himself was unlikely to make any public appearance, but rather to celebrate quietly with his family in his village home of Qunu. His granddaughter Ndileka Mandela told the Sowetan newspaper that his family would celebrate with a traditional meal of tripe and samp, a corn dish popular in his region of the Eastern Cape. \"We will probably have food like samp and tripe, his favourite food,\" she told the paper. \"The big lunch will be at 4:00 pm (1400 GMT) where we will present him with a cake.\" Former US president Bill Clinton met with Mandela at his village home on Tuesday. A photograph released after the meeting showed Mandela seated in an armchair, his lap covered by a blanket, as he held Clinton\'s hand. Images of the Nobel Peace Prize winner have become rare in recent years as he has retired to Qunu. He was last seen in public at the closing ceremony of the 2010 World Cup in Johannesburg.