Enrico Fermi is remembered for his many contributions to theoretical and experimental physics, but from an educational point of view he also popularized the use of the kind of questions we now call “Fermi problems” (or “Fermi questions”). Fermi problems (FPs) are back-of-envelope problems that arose from the need to make order of magnitude calculations, and Fermi himself used them in his own research and physics classes. The procedure proposed by Fermi was to break the original problem down into simpler sub-problems, solve these by making reasonable estimates and educated guesses, and thereby reach a solution to the original question. In the literature, this way of working is known as the “Fermi (estimates) method.”

1.
Fermi Questions” is the name of the column in The Physics Teacher journal in which these types of problems are presented and discussed.
2.
Jonas
Ärlebäck
and
Lluís
Albarracín
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The use and potential of Fermi problems in the STEM disciplines to support the development of twenty-first century competencies
,”
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979
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2019
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3.
Andrew W.
Robinson
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Don’t just stand there—Teach Fermi problems!
Phys. Educ.
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87
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2008
).
4.
Haytham M.
Barahmeh
,
Adwan M. B.
Hamad
, and
Nabeel M.
Barahmeh
, “
The effect of Fermi questions in the development of science processes skills in physics among Jordanian ninth graders
,”
J. Educ. Pract.
8
,
186
194
(
2017
).
5.
Sean M.
Cordry
, “
Thermodynamics and human population
,”
Phys. Teach.
48
,
403
-
407
(Sept.
2010
).
6.
David L.
Morgan
, “
Measuring the effect of an astrobiology course on student optimism regarding extraterrestrial life
,”
Int. J. Astrobiol.
16
,
293
295
(
2017
).
7.
Lluís
Albarracín
, “
Large number estimation as a vehicle to promote mathematical modeling
,”
Early Child. Educ. J.
49
,
1
11
(
2021
).
8.
Andrea
Peter-Koop
, “Teaching and understanding mathematical modelling through Fermi-problems,” in
Tasks in Primary Mathematics Teacher Education
(
Springer
,
Dordrecht
,
2009
), pp.
131
146
.
9.
Nora
Haberzettl
,
Stephanie
Klett
, and
Stanislaw
Schukajlow
, “Mathematik rund um die Schule—Modellieren mit Fermi-Aufgaben,” in
Neue Materialien für einen realitätsbezogenen Mathematikunterricht 5. Ein ISTRON-Band für die Grundschule
(
Wiesbaden
,
Springer Spectrum
,
2018
), pp.
31
41
.
10.
Irene
Ferrando
and
Lluís
Albarracín
, “
Students from grade 2 to grade 10 solving a Fermi problem: analysis of emerging models
,”
Math. Educ. Res. J.
33
,
61
78
(
2021
).
11.
Jonas
Ärlebäck
, “
On the use of Realistic Fermi problems for introducing mathematical modelling in school
,”
Math. Enthus.
6
,
331
364
(
2009
).
12.
Lluís
Albarracín
and
Núria
Gorgorió
, “
Students estimating large quantities: From simple strategies to the population density model
,”
Eurasia J. Math. Sci. Technol. Educ.
14
,
1
15
(
2018
).
13.
Irene
Ferrando
and
Carlos
Segura
, “
Fomento de la flexibilidad matemática a través de una secuencia de tareas de modelización
,”
Avances de Investigación en Educación Matemática
17
,
84
97
(
2020
)
14.
Jennifer A.
Czocher
, “
Introducing modeling transition diagrams as a tool to connect mathematical modeling to mathematical thinking
,”
Math. Think. Learn.
18
,
77
106
(
2016
).
15.
Jennifer A.
Czocher
, “
How does validating activity contribute to the modeling process?
Educ. Stud. Math.
99
,
137
159
(
2018
).
16.
Lluís
Albarracín
and
Jonas
Ärlebäck
, “
Characterising mathematical activities promoted by Fermi problems
,”
Learn. Math.
39
,
10
13
(
2019
).
17.
L.
Weinstein
,
Guesstimation 2.0: Solving Today’s Problems on the Back of a Napkin
(
Princeton University Press
,
Princeton, NJ
,
2012
).
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