USING ADDITION TO SOLVE SUBTRACTION PROBLEMS IN THE NUMBER DOMAIN UP TO 20 AND 100

ABSTRACT

Over the past 4 decades, a lot of research has been done on the strategies that are used to mentally solve subtraction problems. In the present manuscript, 2 types of strategies are distinguished: (1) direct subtraction, in which the smaller number is directly subtracted from the larger one (e.g., 75 − 43 = . by doing 75 − 40 = 35, 35 − 3 = 32), and (2) subtraction by addition, in which one determines how much needs to be added to the smaller number to get to the larger one (e.g., 75 − 43 = . by doing 43 + 30 = 73 and 73 + 2 = 75, so the answer is 30 + 2 = 32). We set up a series of 5 related studies using non-verbal methods to investigate the flexible use of these strategies in both single- and multi-digit subtraction, first in adults and then in both typically developing children and children with mathematical learning disabilities. The present article provides an overview of the results of these 5 studies.

Authors: Greet Peters, Bert De Smedt, Joke Torbeyns, Pol Ghesquière, Lieven Verschaffel
 
MENON: Journal Of Educational Research [ISSN: 1792-8494]