EVERY day, children from the slums of Mukuru walk, some of them for more than an hour, just to get to school.
Without an education, the boys and girls who live in cardboard and corregated iron shacks in the slums would be forced onto the streets, with no hope of a brighter future.
But these children have a chance for a better life thanks to the Mukuru Promotion Centre (MPC), supported by the Sisters of Mercy. The MPC has been supported by British Airways for more than ten years through voluntary work and donations.
The airline also sponsors Heathrow Primary School in their work with the MPC.
Without the MPC, the four schools which educate more than 4,000 children from the slums, may not exist.
As we arrive at St Catherine's School in the slum just after 7am, children, dressed haphazardly in mis-matched uniforms, too big, too small, or full of holes, rush through the gates, waving at us, and smiling brightly.
One boy catches my eye. He is probably around eight years old, but is wearing a jumper that would fit a 16-year-old - it is threadbare. His shorts are filthy, and a size too small, and on his feet, he wears bright red Wellington boots.
His friend has shoes around four sizes too big, with a big piece of cardboard poking out of the back to stop them from slipping.
But many of the smiling children bursting through the gates have no shoes at all. The teachers from Heathrow Primary School are spending a week setting up an English' classroom for the children.
They will learn arts and crafts, and music.
It is not the first time the school has visited the children in the slums.
It is a project headteacher John Hobbs started last year with the help of British Airways, and has vowed to continue.
Mr Hobbs said: "When we were here last year, we had noticed that the schools don't have so many things we take for granted in our schools, such as art and craft materials.
"We decided to set up an English classroom to teach art and music because we don't want to interfere with their own curriculum. They have a standard to follow, as do we, so it wouldn't be right for us to try and take over with subjects such as English or Maths.
"We felt it was an ideal opportunity to create a classroom where we could teach them, and also display their work on the walls."
In the English classroom, children shriek in excitement when they see paints and pencils spread out on the desks.
Teacher Amandeep Hayer explains to the excited class how to cut a shape onto a polystyrene tile, roller the poster paint onto it, and turn the tile over onto a piece of paper, creating a stencil.
The children, who have never even used a pair of scissors before, take to it like ducks to water.
Within minutes they are all creating art they never knew they could. They copy some of the work of the children from Heathrow Primary School, which the teachers had taken with them.
They make Van Gogh-style sunflowers, they paint, cut things out and draw portraits.
A small, quiet looking boy called Samuel has made a beautiful painting. He clearly has artistic talent.
He smiles shyly when I sit next to him and tell him how good his artwork is. "Thank you," he says, bowing his head. "I liked doing it. Can I do some more or do I have to finish now?"
None of the children want the lesson to end, and when the bell for break-time goes, the teachers have to force them outside to have their porridge.
This is the only meal many of them will eat all day.
Kenneth Mwaura, 27, art teacher at St Catherine's, is delighted for the children.
He tells me: "I did touch paints like these and have an experience of them for the first time when I was in college. These children are getting such an opportunity, it makes me excited. I am so happy for them that they get the experience."
Mr Mwaura, who took a teaching diploma at college in Nairobi, moves to the side of the classroom so he can sit and play with the poster paints himself.
"I am still a student," he tells me, smiling.
"You never stop learning. This is like being born again."
Miss Hayer says: "The teachers who came here in October last year had told me so much about the children, but I really was not prepared for what I felt.
"How much the children loved to learn, and how excited they were to experience new things. When the bell went and we had to almost push them out of the door to play, I realised how much they wanted and needed to learn. That touched me most."
Mr Mwaura said: "I am always proud of the children.
"We are always winning art competitions, and all the children have ever worked with are basic materials, such as paper, wood, etc.
"The children have won using only these basic materials, and now we have these, I feel they will win x 2."
Mr Hobbs added: "It's been a fantastic experience for my staff. For them to see the challenges these children face every day just to get to school.
"We would not be able to do any of this without the help of British Airways in supporting their local community.
"It is all part of the every child matters' agenda set by the Government, which is about community cohesion, and schools getting involved with schools in other countries. By coming here we have been able to do that tenfold."
Towards the end of the lesson, one girl calls me over to show me her painting.
The teachers have given them paints of red, blue, green, orange, yellow and purple. But she has painted a vase in brown. She holds my hand and points excitedly to the paint tray, where she has mixed some colours together.
"I made brown," she says, beaming.
And it's as if she has invented the wheel.
I feel my eyes stinging as I watch her obvious delight in discovering something so amazing.
Every child, does indeed, matter.