# Number 13 (LS-RS-512)

Everyone knows that 13 is considered the unlucky number but do you know why? In this learning scenario, created by Natalija Budinski, a mathematics teacher from Serbia, students look into the myth of number 13 and learn about prime numbers. The learning scenario is designed for high school students.

## Prime numbers

A prime number (or a prime) is a natural number greater than 1 that cannot be formed by multiplying two smaller natural numbers. The students learn about the mathematical properties of prime numbers by using online materials and a video on the YouTube platform. Below you can see an example of a mathematics task conducted by one of the students.

## Friday the 13th and other superstitions

To increase students’ curiosity and motivation, the next task is to find why one of the prime numbers, number 13, is considered unhappy. Students explore Europeana blog post ‘It’s unlucky Friday the 13th – everybody, stay at home!‘, where they can find more about this topic – an interesting story that is hidden behind it. They find out that the fear of Friday the 13th seems to be a relatively new phenomenon. Now it is the most popular superstition in the world. Quite surprisingly there are more accidents on Friday the 13th in several countries! In addition to Friday 13th, other superstitions linked to number 13 are also explored in the blog.

## Room for discussion

After reading the blog, students prepared poster presentations in pairs and presented their findings to encourage debate. Students discussed different superstitions and prejudices and how they can be debunked with relevant knowledge.

Students developed their critical thinking skills when distinguishing scientific facts from myths and fake facts. They shared their thoughts about the relevance of science and scientific facts in comparison to what we believe. In the discussion, they realized how mathematics and science are relevant and how people who lack the knowledge are prone to believe the different stories.

CC BY 4.0: the featured image used to illustrate this article has been found on Europeana Collections and provided by the Wellcome Collection.