As a child, Victoria Muumbi's parents could not afford to provide her with a proper education. With no other means of supporting her education, she was forced to drop out of school at an early age.
So when local charity Shining Hope For Communities (SHOFCO) started providing free adult classes in basic literacy, she was among the first to sign up.
Now 35 years old and a mother of two, she makes up for lost time with bags of enthusiasm.
"I have done it for two good years, and it is not very easy," she told Al Jazeera as she waited for the day's lesson to begin.
Hundreds of adults have attended the classes since they started two years ago in Kibera.
The majority of students there are women, and they have a diverse range of motivations for learning to read later in life.
Some simply want to be able to fill in government forms without help, while others want to work jobs that require them to be literate.
Victoria, however, has greater ambitions. "When I finish my school I would like to be a businesswoman, I want to work for myself," she said.
Al Jazeera spent the day with Victoria and her fellow students in Kenya's biggest slum.