Avoid using algebraic symbols and mathematical formulas in all but highly technical reports. Symbols should be defined at their first use. If they are numerous, include a separate list of symbols and definitions in the report.
Indent or centre an equation on the line immediately following that in which it is first referred to in the text. Break equations before an equal, plus or multiplication sign. Align a group of separate but related equations by the equal signs.
Keep in mind that equations (a=b) and inequalities (a><b) correspond to sentences in ordinary narrative and must therefore be grammatically correct. The expression a=b is read "(The quantity) a is equal to (the quantity) b." The expression a>b is read "(The quantity) a is greater than (the quantity) b."
When you write E = mc2 you are writing an equation that is read "The amount of energy in a mass is equal to that mass multiplied by the square of the velocity of light." A formula, on the other hand, corresponds to a phrase and thus contains no equivalent of a verb. The formula for calculating E (the amount of energy in a given mass) is mc2 (the mass multiplied by the square of the velocity of light).
Another principle to keep in mind is that equations and formulas can be written in more than one form. This is useful for fitting them on a page. For example,
can be shown as
and thus take up only one line.
© Public Works and Government Services Canada, 2013
TERMIUM Plus®, the Government of Canada's terminology and linguistic data bank
Writing Tools – The Canadian Style
A product of the Translation Bureau