The relationship between writing and math achievement is not well understood. Phonological awareness (PA), working memory (WM), and fine motor skills (FMS) have been individually linked to theories of writing and math, yet are rarely considered together. The current study evaluates the shared cognitive factors underlying writing and math performance, both timed (e.g. fluency/automaticity) and untimed (e.g. spelling and math computation). It does so among third- through fifth-graders (