A.2.1—Mathematical symbols

Symbols condense a relationship: = means equality, ≈ approximation, ∝ proportionality, Δ change and Σ a sum. Read the units and definitions before manipulating an expression.

Translate the symbolic statement into words, identify what is held constant and check that both sides have compatible dimensions.

Rate = change/time means a larger change in the same time gives a larger rate; Δtemperature is a difference, not a new absolute temperature scale.

A symbol’s meaning depends on the equation and context; Δ does not automatically mean “final value”.