4.1 Operational and structural understanding
All types of representation can call forth
operational and structural understanding (Sfard, 1991),
which are also known as procedural and conceptual
understanding (Hiebert and Carpenter, 1992). Thus,
numerical, algebraic and graphical forms can be
interpreted in terms of the operations that underpin them,
or as entities, which have properties and can be operated
on. For example, f (x) = 3x can be interpreted as
implying a multiplication operation, which produces
function values; or might be recognised as representing a
linear function, which can be differentiated.