Unlike many of the fans the 17-times grand slam champion usually encounters, these children hold a special place in the Swiss champion's heart as his charitable foundation is helping to educate them.
Federer showed the children how to play tennis, joined them in a game of hopscotch and read out stories to a captive audience before sitting down with Reuters to chat about the pressures faced by top athletes, being in his South African mother's homeland, and what he hopes to achieve during the 10th anniversary of the Roger Federer Foundation.
Q: Your trip here has coincided with the bail hearing of paralympian Oscar Pistorius. Pistorius's story has put a particular spotlight on sporting heroes. Do you think there's a lot of pressure put on professional athletes?
Federer: Everybody handles it (pressure and stress) differently. My success came gradually, which was helpful, even though I was always considered a great talent, someone who could become world number one. So it wasn't a huge surprise that I made it to world number one and won Wimbledon, but for me it was.
To handle that stardom, the red carpets, the photo shoots, people all of a sudden recognising you and following you in everyday life, it's a bit weird. It's strange and it can have funny effects on you in terms of do you like it or don't you like it. Some people run away from it, some people embrace it, I found a good middle ground.
It's tricky, especially (because) people love fairytale stories; take you down, put you back up, put you down. And obviously the more famous you become, the more great everything seems when things goes well, and the worse they seem when things don't go so well.
I realised that when I was world number one, I would play an average match and people would say 'you played so well, it's unbelievable'. And when I would play incredibly they would say 'oh my god, we've never seen this tennis before in my life'. So it's always an exaggeration, the whole thing, and that's what we live in, unfortunately.
Q: So are we paying undue attention to Pistorius because of who he is?
Federer: This is now a particular story, it's very difficult. You can't compare this one to any other....
Q: How important is it to take time out?
Federer: For me vacation and family time is as important as training. So I try to take to take at least 10 days if not two weeks of holiday. After the Australian (Open in January) I took two weeks of vacation, all I did was spend time with my family.
I couldn't handle this daily stress of people recognising me, signing autographs, doing press, playing matches, the pressure, people always in my face.
I need to get away from it all. So that when I do come back to the game, I'm hungry, and I'm in the mood to sign autographs, I'm in the mood to do interviews. Not that it becomes a drain and it becomes a burden, because when it's that, the fun goes away then you stop, it's just as simple as that.
Q: It's been a decade since you set up the Roger Federer Foundation which funds pre-school and primary education in Africa and Switzerland. What are you doing to mark the anniversary?
Federer: We were thinking of doing different things. Most important was that I definitely do the trip this year, that has been my number one priority. I went to Ethiopia a few years ago but I really wanted to come back to South Africa.
My heart is in South Africa, through my mum. My mum being from here, me spending a lot of time here as well, I feel most connected to this part of the world.
Obviously I would like to see other ones (projects in the five other African countries) as well, but coming here, being able to do something in South Africa and also visiting my family was important.
The 10 years are important to us. I still feel we're in the beginning of everything. Ten years sounds like a long time but it's changed a lot in terms of the kids we're able to reach and the money we're able to put out there to help.
In this regard I was thinking of doing another 'Match for Africa' again which I did two or three years ago with (Rafa)Nadal when I was able to raise up to $3 million. I don't know if this year will be the year to do it but I hope to.
Q: Is it important for people in your kind of position to 'give back'?
Federer: Sometimes it's not always about the money. If people were willing to give time, to talk, to inspire, to help; because at the end of the day it comes down to the people who help the kids get smarter and get better at the end of the day.
Of course you need money to be able to do that sometimes, not everywhere in the world, but here particularly you do, its clear, its visible.
Q: Is it important to do it?
Federer: I think you have to do what you feel is right to do. I don't think there's a certain obligation, but it would be a missed opportunity if you didn't because, let's not forget how incredibly lucky... I can only speak for myself; how incredibly lucky I feel that I made my hobby my job and my dream at the end of the day.
Sometimes with little effort I can raise so much awareness or raise so much money in one event, that other people would take a long long time to raise - I feel I would be selfish if I were to not share that with other people.
Q: Your twin daughters are almost four years old now. Does having a family make you better or slow you down?
Federer: I thought it would maybe slow me down a bit just because everybody says so. I'm happy that again I was able to prove that its possible to have a family and play well. Not only do I have a family but I have twin girls, so it was super intense in the first years, it's still very intense now. But I made it work. I have an incredible wife who is so supportive and is willing to travel.
At (the) Rotterdam (tournament last week) I was by myself, and I didn't feel the same. Maybe that's one of the reasons I didn't play well, who knows? I miss them much.
I'm happy that I'm able to combine both at the same time. Nine, 10 years ago I never thought of me being a dad, playing tennis, winning the big titles.
In the dream or vision, you always see yourself with the trophy, but you never see yourself with the trophy looking at your kids like what happened at Wimbledon last year. I'm happy I had the opportunity to live through that, those memories will be with me for a lifetime.
NB: The Roger Federer Foundation supports 40 pre-schools in Limpopo province and spends over $3 million a year on educational projects in South Africa, Botswana, Zambia, Zimbabwe, Malawi, Ethiopia and Federer's home country Switzerland.
Over 50,000 children benefited from the foundation's efforts in 2012 to improve quality education in pre-schools and primary schools.