During the past 15
years, the research of Hannula-Sormunen and colleagues has identified
Spontaneous Focusing On Numerosity (SFON) as an important contributor to
young children’s mathematical development. Recently, the development of
SFON has attracted the interest of an increasing number of researchers
worldwide, providing new insights into this important mathematical
competency. This article critically discusses the contribution of recent
empirical studies on SFON, thereby focusing on issues concerning the
measurement, development, and enhancement of SFON. Results indicate the
need for more research on the psychometric characteristics of the
existing SFON tasks and the development of new ways to assess SFON
tendency. Furthermore, studies shed light on remaining theoretical
questions concerning the developmental origins, underlying mechanisms,
and nature of SFON. Finally, SFON enhancement appears to be a promising
tool for promoting young children’s mathematical development.