Sir Gareth, president of Wolfson College, Oxford, led an inquiry five years ago into the future supply of scientists. His report informed Gordon Brown's 10-year strategy on science and technology, and paved the way for an 18-month investigation into the state of secondary maths.
Derek Bell, chief executive of the Association for Science Education, said:
"He was a great champion of science, engineering, technology and maths teaching, not just in terms of their importance for serious science, but in relation to the entire culture of this country."
Sir Gareth, who also chaired Setnet, the Science, Engineering, Technology and Mathematics Network, is understood to have been working until last week. He died of cancer. He was 66.