Maths

Quantity calculus

By 2007-01-01T00:00:00

An apple among oranges (Quantity calculus - remember that apples can't be added to oranges)

Source: istockphoto

Tips for teaching maths skills to our future chemists, by Paul Yates of Keele University

The IUPAC Compendium of Chemical Terminology defines quantity calculus as 'algebra with quantities where the symbols of quantities represent products of numerical values and their units'.1 Put more simply: include the units when substituting values into an equation. The word 'calculus' in this context indicates the computation of symbols, where symbols represent units. In contrast, 'calculus of variations' refers to differential and integral calculus.2

Why is it important?

The use of quantity calculus ensures that we obtain the value for any calculated quantity in the correct units. Is that temperature value in K, o C, or even o F? It also enables us to pick up mistakes in our calculations at an early stage.

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