With schools far away, and little money to pay for transport costs, parents worry about the safety of their children walking to school.
So, a number of parents keep their children at home. Or the child drops out of school: they leave without completing their studies.
These and other barriers to school attendance are the reality for many girls in poor countries.
But now, programs in two developing countries are helping to change that. The programs are giving girls "pedal power" — transportation in the form of bicycles.
Power of the pedal
Rural areas of poor countries often have few secondary schools. So, it is common for students there to travel great distances to attend classes.
Bihar is the poorest state in India. Ninety percent of the state's population lives in rural areas.
Until 2007, too many teenage girls in Bihar were dropping out of school. For Nahid Farzana, her home was 6 kilometers from school. And, her father did not have money for bus fare, she told the Associated Press.
But, that same year, the state government began offering bicycles to girls to help them get to school. The program has been so effective that three nearby states are now doing the same.
And the results are measurable. A 2014 study found that giving bicycles to teenage girls in India increased their secondary school enrollment by 30 percent. It also helped many of them stay in school long enough to take their final exams.
Western Kenya is experiencing success with a similar program. Until recently, there was a high risk of local girls dropping out of school and then becoming pregnant.
Loise Luseno is a 16-year-old girl from Kakamega, Kenya. In the past, she had to walk about 10 kilometers to reach school. Last year, she dropped out temporarily because of the distance.