Mysterious Subtractions

Autor/inn/en	Hillen, Amy F.; Watanabe, Tad
Titel	Mysterious Subtractions
Quelle	In: Teaching Children Mathematics, 20 (2013) 5, S.294-301 (8 Seiten) PDF als Volltext Verfügbarkeit
Sprache	englisch
Dokumenttyp	gedruckt; online; Zeitschriftenaufsatz
ISSN	1073-5836
Schlagwörter	Subtraction; Mathematics Instruction; Mathematical Logic; Validity; Elementary School Mathematics; Teaching Methods + Suchen Sie Ihr Suchwort? Subtraktion; Mathematics lessons; Mathematikunterricht; Mathematical logics; Mathematische Logik; Gültigkeit; Elementare Mathematik; Schulmathematik; Teaching method; Lehrmethode; Unterrichtsmethode
Abstract	Recent documents suggest that all students, even young children, should have opportunities to engage in reasoning and proof (CCSSI 2010; NCTM 2000, 2006, 2009). One mathematical practice that is central to reasoning and proof is making conjectures (CCSSI 2010; NCTM 2000; Stylianides 2008). In the elementary grades, "formulating conjectures and assessing them on the basis of evidence should become the norm" (NCTM 2000, p. 188). When given opportunities to formulate conjectures, students will make conjectures that turn out to be true as well as those that turn out to be false. Even false ideas "often are opportunities for important mathematical discussions and discoveries" (NCTM 2000, p. 191). Therefore, teachers may not want to restrict their students' work to situations in which only true conjectures are formulated and may even want to intentionally set up situations in which students will likely formulate conjectures that turn out to be false. In this article, the authors share a task in a mathematical context that affords children opportunities to make conjectures and prove (or disprove) them. They also offer insights on teaching a 50-minute lesson centered on this task and suggest ways to extend the task to afford even more prospects for children to engage in reasoning and proof. They invite readers to consider how they might use or adapt the task and the enactment we describe for use with their own students. (ERIC).
Anmerkungen	National Council of Teachers of Mathematics. 1906 Association Drive, Reston, VA 20191-1502. Tel: 800-235-7566; Tel: 703-620-3702; Fax: 703-476-2970; e-mail: orders@nctm.org; Web site: http://www.nctm.org/publications/
Erfasst von	ERIC (Education Resources Information Center), Washington, DC
Update	2017/4/10