Single sex education fell out of favor in the 1970s but appears to be making a comeback. Cheyenne High School in North Las Vegas has single sex classes.
Starting Friday, federal laws are changing to allow public schools more range in teaching boys and girls separately.
At the Young Women's Leadership Academy in Queens, New York, boys are not part of the equation. The school has become a model for single sex education.
But while some statistics show single sex schools boost performance for both girls and boys, the president of the National Organization of Women says that may not always be the case.
"We think that it's more likely when boys and girls are separated that they will have stereotyped ideas about each other. After all, school is the workplace of childhood," said Kim Gandy, N.O.W. president.
The U.S. Department of Education is hoping to replicate single sex programs in public schools by giving more latitude to teaching girls and boys separately. the enrollment would be voluntary.