On the first day of a three-day visit to the continent, the prime minister insisted trade deals with countries like South Africa would be a prize for "global Britain" after it leaves the European Union next year.
The visit, her first to Africa as Prime Minister, will also take her to Kenya and Nigeria, making her the first British leader to visit the sub-Saharan region since 2013.
The Prime Minister gave the Mendi bell to South African President Cyril Ramaphosa in a ceremony at Cape Town's presidential office.
She added: "However, for a variety of reasons the private sector has not yet managed to deliver the level of job creation and investment that many African nations need".
"They understand fully well the UK's predicament and they have a multitude of other trade partners, including China, India and Russian Federation", he wrote in a note.
Speaking to the BBC, Fox said: "Some of us remember the supposed economic shock we were going to get if Britain voted to leave the European Union and the result of the referendum itself was going to cost us half a million jobs, it was going to see investors desert the United Kingdom and our economy plunge into recession".
Theresa May has tried to reassure Brits a no-deal Brexit would not be the "end of the world".
Investment from France, which maintains close ties with its former colonies in West Africa, stood at 38 billion pounds ($49 billion) and from China, rapidly becoming a major player in Africa, 31 billion pounds (40 billion). There were no immediate details about the initiative.
The scholarship will now be open to 100 more African students.
Watch and found out why British Prime Minister Theresa May is dancing with school children in Cape Town, South Africa.
It was the worst maritime disaster in the African country's history, and has become a symbol of its Great War sacrifice.
The Mendi bell was found and restored previous year after being lost from the shipwreck in the 1980s. "If we fail to do so, the economic and environmental impact will soon reach every corner of the world".
In Nigeria the Prime Minister will meet President Muhammadu Buhari in Abuja and spend time in Lagos meeting victims of modern slavery - a cause Theresa May has worked passionately to tackle.
On Thursday she will meet Kenyan President Uhuru Kenyatta, shortly after his return from seeing US President Donald Trump in Washington.