Have you ever tried asking some Fermi questions?

One questioning strategy worth trying in class is ‘Fermi questions’.

Fermi questions are named after the physicist and Nobel Prize winner Enrico Fermi.

He challenged his students to use estimation, common sense and numerical reasoning to work out quantities that were difficult or impossible to measure. He deliberately posed questions with limited information so that students had to ask more questions. His questions emphasise the process rather than the answer.

#### Examples of Fermi questions

***** How many times could you say the alphabet in 24 hours?

What a great selection of Fermi questions. I can understand why students would enjoy them, and see their potential to get students thinking and discussing.

can you post some of the possible answers?

Haha – which one?

the Earth to Moon one is 8.770248688 Years walking 5Km/h. the distance is 384,400Km

I have a bottom set of dispirited kids who talk or draw and reject the formal learning. I’m going to try a question from this list, to see if it sparks their attention. Thanks!

Let me know if you need anything else…

Thanks, I wrote the list and there’s plenty more where they came from!

Fermi questions are on the syllabus for the Core Maths exam. Some great ideas here for the next time I teach it.

Good to know!

“When you take a single breath, how many molecules of gas you intake would have come from the dying breath of Mahatma Gandhi ?”

How much air has been exhaled by Mahatma Gandhi in his last breath?

What is the volume of air in earth’s atmosphere? Radius of the Earth(RE) is approximately 6,400 km and 100 km is often used as the border between the atmosphere and outer space. But, 75% of the atmospheric air is within about 11 km of the surface.

What fraction of Gandhiji’s last exhaled air is present in a unit volume of atmosphere? we assume that during these 70 years it’s evenly distributed in earth’s atmosphere.

How many air molecules you inhale in each breath?

What are the chances that your current inhaled air contains air from Gandhiji’s last breath?

Can you please share possible answers of these questions

There are so many possibilities, that would make it too easy for you and others reading…

Very good and resourceful

I put one on the wall (and on Google Classroom) each Monday morning for my students to discuss and play with during our staggered starts and finishes. I have a year 6 class and about half of them really enjoy it. The rest either ignore it or think it’s silly. I don’t make a fuss, just support and encourage the ones who want to try them. It has made some of my less mature children think a bit more critically and organise their thinking in problem solving during maths lessons.

A good effort nonetheless; perhaps an engaging image alongside the fermi question will work wonders?

Great to see some many people interested in this Topic – Fermi questions are so valuable for maths thinking and inclusive of all as you can respond with simple or complex solutions.

One thing to consider is relevance. Shouldn’t we try and ask questions that are worth answering.

Why ask – “How many pieces of popcorn does it take to fill a cinema?” (who cares!!) – when you can ask “How many people can you fit in a cinema and still observe social distancing rules?”

I usually have some criteria for my Fermi questions – they need to be

Meaningful (worth knowing)

Achievable

Relevant (to the student cohort)

Challenging (involving enough maths for complex answers as well as simple solutions”

Agree – it’s a fantastic methodology.