(2004). Strategy choices in simple and complex addition: Contributions of
working memory and counting knowledge for children with mathematical disability.
Journal-of-Experimental-Child-Psychology. Vol 88(2) Jun 2004, 121-151.
Groups of first-grade (mean age = 82 months), third-grade (mean age = 107
months), and fifth-grade (mean age = 131 months) children with a learning
disability in mathematics (MD, n = 58) and their normally achieving peers (n =
91) were administered tasks that assessed their knowledge of counting
principles, working memory, and the strategies used to solve simple (4 + 3) and
complex (16 + 8) addition problems. In all grades, the children with MD showed a
working memory deficit, and in first grade, the children with MD used less
sophisticated strategies and committed more errors while solving simple and
complex addition problems. The group differences in strategy usage and accuracy
were related, in part, to the group difference in working memory and to group
and individual differences in counting knowledge. Across grade-level and group,
the switch from simple to complex addition problems resulted in a shift in the
mix of problem- solving strategies. Individual differences in the strategy mix
and in the strategy shift were related, in part, to individual differences in
working memory capacity and counting knowledge. (PsycINFO Database Record (c)
2006 APA, all rights reserved) (journal abstract)