Stiff studied mathematics at the University of North Carolina at Chapel Hill, graduating in 1971, and went on to earn a masters degree from Duke University in 1974 and a doctorate in mathematics education from North Carolina State University in 1978.
Stiff"s father was "a factory worker with only a third-grade education". After teaching mathematics at the middle school and high school levels, and then holding a faculty position at the University of North Carolina at Charlotte beginning in 1978, he returned to North Carolina State University in 1983. Under his leadership, the National Council of Teachers of Mathematics pushed for a greater emphasis on basic computational skills in elementary and secondary school mathematics education, and for an appropriate emphasis on conceptual understanding.
Stiff rejected simple solutions to complex issues, saying that "Back to basics is moving backward.
Number-crunching alone is no longer enough." Instead, Stiff has recommended better training and incentives for mathematics teachers, a teaching style that incorporates a variety of ways of looking at the same material, and an attitude that all students can learn mathematics regardless of their background. In 1995 he was a Fulbright scholar in Ghana.
In 2009 he was an North Carolina State University College Distinguished Award recipient, and in 2010 the North Carolina State University College of Education gave him their Distinguished Alumni Award.
