A considerable body of research exists on students’ understanding of decimals and the
prevalence and persistence of misconceptions (Steinle & Stacey, 2003). Much of this
knowledge has been inferred from responses to pencil and paper decimal comparison tests.
When students are asked to choose the larger of two decimals they are commonly
categorised as using one of three erroneous rules. Sackur-Grisvard and Leonard (1985)
defined three systematic but incorrect rules that fourth and fifth grade French students used
to decide which decimal number was greater: