Two Perspective on Addition Development
Arthur J. Baroody, Sirpa Tiilikainen · 2013
Over the last three decades, researchers have discovered that children, even preschoolers, have surprisingly powerful everyday (informal) arithmetic knowledge (e.g., Carpenter, Hiebert, & Moser, 1983; Fuson, 1982; Ginsburg, 1977; Huttenlocher, Jordan, & Levine, 1994; Mix, Levine, & Huttenlocher, 1999; Starkey & Gelman, 1982). Consider the case of Alexi, who had not yet begun school (formal) instruction on arithmetic. While playing a mathematics card game with his father, the 7-year-old formed the following number sentence: The boy announced that the sum represented by the wild card was eight. Asked how much six and three was, Alexi put out five fingers on his left hand, one on his right hand, and then three more on his right hand. After counting the fingers, he commented quizzically, “Nine? Nine? I thought 4+5 was nine.”