We discuss the importance of the ordering of symbols in physics formulas and identify implicit conventions that govern the “standard” form for how formulas are written and interpreted. An important part of writing and reading this form is understanding distinctions among constants, parameters, and variables. We delineate these conventions and encourage instructors to make them explicit for students.

1.
Robert H.
Romer
, “
Reading the equations and confronting the phenomena-The delights and dilemmas of physics teacing
,”
Am. J. Phys.
61
,
128
142
(
Feb. 1993
).
2.
Paul G.
Hewitt
, “
Equations as guides to thinking and problem solving
,”
Phys. Teach.
49
,
264
(
May 2011
).
3.

Discussion and follow-up interview with student in calculus-based introductory course for science and engineering students.

4.

In advanced courses, especially those in high energy or particle physics, common practice is to use a system of units such that ħ=1 or c=1 and the like. However, this is not common at the introductory or intermediate level, so we ignore it here.

5.
Regarding parameters we closely follow the discussion in
Andrew F.
Rex
and
Martin
Jackson
,
Integrated Physics and Calculus
(
Addison-Wesley
,
New York
,
2000
), p.
39
.
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