Along with several colleagues, he provided individual tutoring in mathematics and science for students who were falling behind.
That tutoring continued after school and on weekends.
He also visited students' homes and met their families.
The purpose was not simply to tell parents that a child needed better grades.
He wanted to understand why the child was struggling.
Was there food at home?
Was the family dealing with financial problems?
Was something preventing the student from attending school?
Was the student under pressure to leave education?
By understanding the circumstances outside the classroom, teachers could respond more effectively to what happened inside it.
This was education treated not simply as the transfer of information, but as a relationship between a school, a student, a family and a community.
One Computer — But No Excuses
Teaching science in a poorly equipped school presented an obvious problem.
Modern science education benefits enormously from technology.
Keriko had almost none.
One computer with an unreliable internet connection had to serve a school full of students.
Tabichi found ways around the limitation.
According to his Global Teacher Prize profile, he incorporated information and communications technology into approximately 80 percent of his lessons despite the school's lack of reliable internet access.
How?
He went elsewhere to find the internet.
Tabichi visited internet cafés, downloaded educational materials and saved online content so that he could use it offline with his students later.
It was an improvised solution to a technological problem.
If the internet couldn't reliably come to his classroom, he would bring pieces of the internet back with him.
That approach reflected a larger philosophy.
Limited resources were real.
They mattered.
But they did not have to define what his students were capable of achieving.
Turning Students Into Scientists
Tabichi believed his students needed more than lectures and textbooks.
They needed opportunities to discover what they could create.
He established a talent-nurturing club and expanded the school's Science Club, encouraging students to design research projects and solve problems.
The results were striking.
According to the Global Teacher Prize, 60 percent of the students involved in these projects eventually qualified for national science competitions.
Students from this poorly resourced rural school began competing against students from some of Kenya's strongest schools.
At the Kenya Science and Engineering Fair in 2018, students Tabichi had mentored developed a device designed to help blind and deaf people measure objects.
Keriko went on to finish first nationally in the public-schools category.
For a school with one computer and intermittent internet, that was an extraordinary achievement.
But it wasn't the end.
The school's Mathematical Science team also qualified for the Intel International Science and Engineering Fair in the United States.
Two students later represented Kenya at the 2019 event in Phoenix, Arizona, where, according to a later Global Teacher Prize account, they received a United Nations Sustainable Development Goal award.
For those students, the journey was about more than winning a competition.
It demonstrated something powerful.
Where you begin does not necessarily determine where your ideas can take you.
The Numbers Started Changing
Science competitions produced dramatic stories, but another transformation was taking place in the everyday life of the school.
More students were staying engaged with education.
Enrollment increased significantly.
According to the Global Teacher Prize's 2019 profile, enrollment at Keriko doubled to approximately 400 students over three years.
Discipline problems fell dramatically as well.
Reported cases of indiscipline dropped from around 30 per week to approximately three.
And more students began moving on to higher education.
In 2017, only 16 of 59 students went on to college.
A year later, 26 students progressed to university or college.
Girls' academic performance also improved significantly. By the period described in his prize profile, girls were outperforming boys across four tests administered during the previous year.
Those statistics matter because they reveal what Tabichi's work was really accomplishing.
This wasn't simply about producing a few impressive science projects for competitions.
The culture surrounding students was changing.
More young people were beginning to believe that education could lead somewhere.