Covid-19 tests: probabilities

Bayes’ Theorem is applied to medical tests, to calculate the probability of being infected with a virus, given a positive or negative test result. What drives the uncertainty is false negative results, or false positive results. In this article, I give a practical outline as to how one can interpret one’s test result, after calculating the relevant probability using Bayes’ Theorem.

To start off with, we need two estimates. For a negative covid-19 test, we need the rate of false negative results, and the current actual prevalence of the disease in the community. On the other hand, for a positive covid-19 test, we need the rate of false positives, and the current prevalence of the disease. False outcomes in tests vary according to the laboratory doing the test, and probably also the skill with which each individual test is carried out, but, for the sake of a rational understanding of the usefulness of these tests, we can use common statistics to calculate feasible probabilities.…

By | January 1st, 2021|News|0 Comments

The South African Mathematics Olympiad

The South African Mathematics Olympiad is an annual mathematics competition for high-school students in South Africa. The competition is organised by the South African Mathematics Foundation, and comprises three rounds which increase in difficulty. The final round of the 2019 South African Mathematics Olympiad will take place on Thursday, 25 July, and the top ten junior (Grade 8 and 9) and senior (Grades 10—12) competitors will be invited to a prize-giving evening taking place on 14 September 2019. At the same time, the problem selection committee will meet to start setting the 2020 papers.

According to the SAMF, nearly 100000 students participated in the 2017 edition of the competition. The numbers for the 2019 competition are likely to be similar. These students all write the first round of the competition, which learners write at their individual schools in March every year. The papers are marked at the school, and any student with more than 50% is invited to participate in the second round of the competition.…

By | July 11th, 2019|Competition, English, Event, News|8 Comments

Numeric Teaching Fellowships – Applications Now Open – Please Share!

Enjoy teaching?

Passionate about Maths?
Want to earn your teaching qualification?
Apply for a Teaching Fellowship with the 
The Numeric Teaching Academy (NTA) provides Teaching Fellowships for university graduates to train to become maths teachers. This one-year program consists of three main components: the post-graduate certification in education (PGCE) through UNISA (distance learning); content, practical and classroom management workshops at the Academy; and a teaching internship at one of Numeric’s afterschool programs in Khayelitsha, Mfuleni or Mitchells Plain.
Teaching Fellowships are fully funded and cover the cost of tuition, textbooks, a laptop, and a monthly living stipend.
It is an intensive, yet rewarding program in which you will learn much about mathematics, teaching, and yourself. Students who apply and are accepted join a vibrant and friendly community of people who are passionate about maths education and who believe that education is the most powerful driver of change in society. 
By | May 31st, 2017|Advertising, News|0 Comments

Greetings from Bibliotheca Alexandrina

I just received the info below on Bibliotheca Alexandrina and its new African Networks and I thought it makes sense to share it on mathemafrica. I really like the idea of historical places connecting to new technologies. Here is a link to a film (in French) about the historical library at Alexandria:


Greetings from the Bibliotheca Alexandrina (BA) in Egypt. We are pleased to announce the launch of “BA African Networks”. Below you will find a description of the networks. You are most welcome to explore our portal and our five networks through the following link.

The Bibliotheca Alexandrina (BA) follows in the footsteps of the Ancient Library of Alexandria as a meeting point for cultures and civilizations. It aims to rise to the digital challenge in order to develop African innovation through the use of science and technology in networks that extend throughout Africa. The new goal set by the BA is to connect those with common interests and expertise to hasten the development of knowledge and enable immediate sharing of knowledge and contributions.

By | April 7th, 2016|English, News, Uncategorized|0 Comments

Mathemafrica and the Next Einstein Forum (NEF) #1

Dear Mathemafrica readers,

I am sitting at the AIMS-Senegal institute in Mbour (about 1.5 hours drive South of Dakar) and together with my team member Sebastian and the AIMS-Senegal staff and students, we are preparing an interactive mathematics exhibition (as part of the IMAGINARY – open mathematics project).. It will be shown as of March 8 at the Next Einstein Forum (NEF), to be held at a huge conference venue just outside Dakar.

There will be many ministers, scientists, politicians, even presidents from (apparently all fifty-four) African countries – and also many international guests – joining the NEF, with the goal to discuss about scientific innovations, collaborations and solutions in Africa!

We have to plan to blog live from the NEF, with insights and views from participants. And of course, we will let you know about our exhibition, about a new competition, we will launch and everything happening around!

Prepare yourself for the NEF at:

And the Twitter hashtag: #AFRICASEINSTEINS

Please find a picture from our first technical setup yesterday at the AIMS Institute.…

By | March 6th, 2016|English, Event, News, Uncategorized|0 Comments

The experience of mathematical beauty and its neural correlates

Check out a mathematics and neuroscience paper here, whose authors include Fields and Abel medalist Michael Atiyah.

Untitled 2 published in frontiers in human neuroscience.

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By | October 14th, 2015|English, Level: intermediate, News|0 Comments

Attracting women and girls to careers in physics – video seminar on the 6th of August

Attracting women and girls to careers in physics

This seminar may be attended via video conference in Pretoria, Cape Town and KwaZulu-Natal. Details are indicated below.

The HSRC Seminar Series In collaboration with the Africa Institute of South Africa

Speaker: Dr Malebo Tibane, Department of Physics, Unisa,

Discussant: Dr Palesa Sekhejane, HSRC

Chair: Prof. Narnia Bohler-Muller, HSRC

Venues in Pretoria, Durban and Cape Town (Videoconferencing facilities: see below)

Date: 6 August 2015

Time: 12h30 – 14H00

Representation of girls and women in the Physics related sector is declining or stagnating globally and locally. Therefore, issues that hamper on the development of women to participate equally in male-dominated spheres need to be discussed and captured adequately to create an enabling environment for women and girls in the sciences, and physics in general. In November 2005 Women in Physics in South Africa (WiPiSA) was launched, with funding from the Department of Science and Technology (DST) and under the auspices of the South African Institute of Physics.…

By | July 19th, 2015|Advertising, Conference advert, English, Event, News|0 Comments

UCT is hiring in Mathematics/Applied Mathematics

Please spread the following advertisement to anybody who may be interested in a standard academic position or teaching only position in the Maths and Applied Maths department at UCT:

Job Advertisement

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By | May 8th, 2015|English, Job advert, News|0 Comments

3rd International Workshop on Nonlinear and Modern Mathematical Physics 9-11 April 2015, Cape Town, South Africa

Check out the following conference happening near Cape Town in April:

3rd International Workshop on Nonlinear and Modern Mathematical Physics 9-11 April 2015, Cape Town, South Africa


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By | March 2nd, 2015|Conference advert, English, News|0 Comments

Presentation of the Mathemafrica framework to an Italian audience

Today I am presenting some of the ideas behind the Mathemafrica project to an Italian meeting, discussing the outcomes of the AIMS-imaginary meeting last month. The presentation can be found here:

Mathemafrica – Italian discussion

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By | December 17th, 2014|Background, English, Level: Simple, News|1 Comment