Reading to Learn? The Co-Development of Mathematics and Reading During Primary School Nicolas H Christine Merrell Helen Cramman John Little David Bolden Benjamin Nagengast preprint DOI: 10.31219/osf.io/v8h29 → “Understanding how early reading and mathematics co-develop is important from both theoretical and pedagogical standpoints. Previous research has provided mixed results, with some studies suggesting that mathematics is the leading indicator in this developmental process, whereas others have suggested that reading is. This paper investigates the development of reading and mathematics in a longitudinal sample of N = 355,883 students from the UK aged 5 to 12 (49% girls). The results suggest a positive relation between the development of the two domains. In addition, a statistically significant positive association between prior reading scores and subsequent changes in achievement in mathematics was found, whereas changes in reading were substantially smaller for students with a higher prior performance in mathematics.”