Emigdio Rodriguez, the Bolivian programme co-ordinator in Sucre, said:
"Most illiterate learners are already familiar with numbers from handling money. All of them have to buy goods in their daily lives. So, the methodology moves from the known - numbers - to the unknown - letters."
It was developed by Cuban literacy expert, Leonela Relys, of the Latin American and Caribbean Pedagogical Institute in Havana.
The method is centred on 65 two-hour video-based classes spread over three months. The first four focus on revising the numbers between zero and 30.
The students are then taught the vowels, then consonants, linking each letter to a number. The programme - which has received honourable mentions from Unesco - involves three components: listening and seeing; listening and reading; and listening and writing.
Ana Maria Echavarria, a Bolivian supervisor, said: "We try to make the video classes as relevant to people's lives as possible. That's why they feature Bolivian soap stars. The topics relate to the home, a street market, the family, agriculture, the environment, and so on."
The approach involves looking at a familiar illustration related to the video. The learners repeatedly read and write a key word, then break it down into syllables. The facilitator then teaches them to use the syllables to form new words. Each student takes an exam at the end of the programme to determine whether they have achieved basic literacy.