Prime Minister David Cameron said the Government took the decision to change the national curriculum now because "we are in a global race".
Mr Cameron told This Morning: "We need to make sure the standards we set are as tough as those on the other side of the world.
"If we want to turn out young people who take on the world and win we've got to be rigorous at school".
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A GoFundMe page was set up by the children's uncle to raise £15,000 for their funerals.
Lindsay Hoyle said his "family will never be the same" after the death of his 28-year-old daughter Natalie.
Police say they have traced four drivers who are thought to have hit the woman, and added that a fifth vehicle may also have been involved.