Challenge    I was working as a Diploma Programme (DP) Mathematics Educator at an International  Baccalaureate (IB) Organisation. I had a very differentiated set of students in my class. I had  observed students ​struggling with mathematics in spite of their motivation, sound mathematical  knowledge, and explicit instructions delivered to them. There could have been various reasons  behind the challenge like erroneous recall of arithmetic facts, difficulty in representing mathematical  concepts etc. ​DP mathematics courses serve to accommodate the wide range of needs,  interests, and abilities of students. Keeping all these things in mind, introducing a new topic in  class (Geometric Series) through just chalk and talk method did not seem like a convincing idea.    Selection    It is a common belief that stories can be used to teach mathematics to primary school students  but not for high school students. However, stories are a powerful cognitive tool that can help in  providing meaning to seemingly irrelevant facts, methods, and algorithms. The purpose of  storytelling in a math class is to create an environment of imagination along with thinking, to  make mathematics more enjoyable for students, to help them understand ideas and concepts,  and to bring a ​moment of relaxation to the class​.    Historical anecdotes can often be woven into teaching and math is rooted in history since time  immemorial, offering enough opportunities for storytelling. We can even engage students in  mathematical activities through storytelling.    Application    Students are already familiar with “word problems”. To effectively use word problems in a high  school math classroom, they need to be reconstructed a bit. To introduce Geometric Series and  make the students derive its formula by themselves in class, I decided to infuse word problems  with dynamic characters and plots, that is, come up with a story. To make it even more  engaging for the students, I also decided to have the students perform a paper cutting activity  with this and make them translate words into abstract equations.  The story went like this: There was a king who had a son, who used to pester him to give him  the land owned by the king. The king was in a critical situation and decided to give the land but  according to some rules. The king told him that he only had a square piece of land and he would  give half of that on the first day, half of what he gave the previous day on the second day and so  on. After doing so for many days, how much of land would his son have?   Students went on to find the answer to that question using the square papers they had. They  folded the square in half into two equal triangles (one such triangle was what the son got on the  first day). They again folder the other triangle into two equal halves, cut them out and kept one  of the new triangles as the son’s share for the next day. They realised that the king can do this  forever but he would still have a small triangle left with him. So the son can never get the whole  land!

Insight     The storytelling discussed here took the form of a structured activity in the class. ​Students were  able to summarize the solution to the problem. It helped my students unearth the symbolic  nature of verbal strategies. My students discovered that the sum of infinite such triangles would  be 1. They were able to come up with the sum of an infinite geometric series own their own, all  of which started with a story.     The students will look forward to reading more such ‘stories’ in math classes and try finding  solutions to the mathematical problems embedded within. I discovered that storytelling is a  productive tool for teaching the subject, it even provides a sense of giving beyond the subject  content.    .​Approach    I had incorporated several design thinking tools or activities in my math class and found  storytelling as an effective instructional tool. It is important to review the insights gained from the  application of this tool and incorporate them into future storytelling sessions.    I shared this story with my colleagues (IB educators from various disciplines) and it had a  profound effect on their classroom teaching as well. I would further encourage the use of  storytelling as a starting point for a series of mathematical activities in class.

