Lead
Arithmetic drills: eight out of ten correct. Word problems: total freeze. "How can you do the calculation but not solve the problem?" — that question is usually directed at the child. But word problems genuinely require more than arithmetic. They are not simply harder arithmetic. They are a different kind of task.
"Can calculate but can't solve word problems" is not a skills deficit. It is a bottleneck that emerges when multiple cognitive processes are demanded simultaneously. At the center of that bottleneck is the interaction between working memory and language comprehension.