Multimedia-supported metaphors for meaning making in mathematics

We examined a number-line metaphor presented using interactive multimedia a s a means of helping students build connections between an arithmetic proce dure and their existing conceptual knowledge. Elementary school children le arned to add and subtract signed numbers through a computer-based multimedi a program over 4 training sessions. Participants received 64 example proble ms presented only in symbolic form (single-representation [SR] group) or in symbolic, visual, and verbal forms (multiple-representation [MR] group). I n Experiment I, compared to the SR group, the MR group (a) showed a larger pretest-to-posttest gain for high-achieving students but not for low-achiev ing students, (b) showed a greater gain on difficult problems but not easy problems, (c) learned faster during training, and (d) showed a greater pret est-to-posttest reduction in the use of conceptual bugs reflecting conceptu ally confusion between negative signs and subtraction operators. In Experim ent 2, high spatial ability students in the MR group outperformed low spati al ability students on pretest-to-posttest gain. Productive learning with M Rs is strongest when working memory is not overloaded, so cognitive load an d MR theories can be reconciled.