Questions and answers from 4th graders

A couple weeks ago, I had a wonderful evening thanks to the Skype a Scientist program, a 4th grade class from the US (think 9-10 years old if like me, you have no idea what grades stand for) and their super-dedicated teacher. It was a fun time but the most surprising part was discovering the questions they had prepared. I thought it would be worth it to list them and record some answers as I remember them. I grouped the questions in four arbitrary categories. The list also does not reflect the order in which the questions were asked.

Table of Contents

👨‍🔬 So… you’re a scientist?

Why did you decide to be a scientist?

Curiosity mostly, but also I wanted to challenge myself on open questions.

How did you become a scientist? What school did you go to?

Anyone can become a scientist by doing science, the schools we go matters less than the will to explore science. I guess I became a full-time scientist when I started my PhD two years ago.

What kind of place do you work in?

I work in a “lab”, but in my case this is an office (no white lab coat, no smoking tubes) with two other people. The office is located in a research institute, where other scientists and professors work on their research.

What science experiments do you do?

I write mathematical models to make better decisions in complex environments, for example in power grids. With specific models, the computers are really good at finding the best decisions.

How many days a week do you work?

I work from Monday to Friday, so 5 days. Sometimes I take vacations off, sometimes I work a bit more, depending on the emergency of what I am doing.

What research are you working on?

I am working on models for better decisions in what is called the power grid. The power grid is the network connecting everything to electricity sources. Whether you are in your class or your kitchen at home, when you turn on the light, electricity is flowing all the way from places where it is produced (like the water network). These days, there are more and more renewable sources like solar panels and wind farms, but sometimes there is no sun or wind, so we have to anticipate better what is happening and make our consumption flexible.

🏢 Life in a lab

Have you seen a chemical reaction?

Yes, and so have you! Cooking food on a frying pan for example will start chemical reactions, if you leave it for too long, it’s getting brown and burned.

How much workspace do you have?

If we talk about physical workspace, I use a full table, where I have my laptop, a keyboard, and a mess of papers, draft notes, books. I’m a messy scientist.

Do you any experiments with animals?


What do you do in your lab? (if you work in a lab?)

Once I have developed models and obtained interesting answers from computers, I write articles for other scientists to read. Other than that, I discuss with other people to find ideas on the models we write or how to write better computer programs, I drink coffee and eat cookies even when I shouldn’t.

📈 Maths, again?

Do you make models of anything?

I haven’t found counter-examples yet so I’ll go with yes, you can make models of anything. A model is a way we represent something in a way that is easier to grasp, either for us humans, or for a computer.

How did the language of math get created?

I am not an expert in the history of science, but from what I remember of old mathematical papers I saw, the language of mathematics was created piece by piece, by iterations. First, concepts would be created, like adding two numbers together into a bigger number. Then, some scientist, not necessarily the person who developed the concept, would find way to represent this abstract concept, for example with a cross symbol: $+$.

Sometimes, several ways to represent the same thing would exist in parallel, and people would only agree later on which one should be kept.

See this timeline when different modern symbols were introduced:


Why is math so hard?

Because it’s both:

  1. A new language to learn (how to say or write things)
  2. New concepts (new things we are able to say)

Things get easier with practice once you can relate the concept to things you already know or visualize. That’s also why you are learning multiplications with different models to see which one helps you relate the concept to what it applies to.

How are there so many different strategies for math?

From the explanations the teacher gave me on what the class is working on, the question probably refers to how they learn about multiplications using different visual techniques, like ratio tables or the box & array methods.

The simple answer is that everyone is different, with some people finding easier to understand multiplication using boxes while another would see it clearly with the concept of ratio or lines. Whatever works for you is always the best.

💻 Working with computers

Have you ever seen the inside of a computer?

Yes, a colleague of mine often opens up some workstations to increase their memory. Other than that, I worked at a company building tiny computers one can use in outdoor activities.

Do you help make computers?

No, I use computers every day but have no idea how to build one, it requires very specific skills to make both the physical system (called hardware) and the minimum software component on top.

Have you ever seen a super computer?

Sadly no, but I’d like to!

Have you ever created an app?

I have never created a mobile app alone, but I helped a bit on the app of my previous company. I created some computer apps, one was a snake game (I think the kids were too young to know it, made me feel old).

Mathieu Besançon
Mathieu Besançon
Researcher in mathematical optimization

Mathematical optimization, scientific programming and related.