Recent studies have shown that children with mathematics difficulties (MD) have weaknesses in multiple areas of mathematics. Andersson, for example, recently found that children with MD perform significantly worse than other children on clock reading tasks. The present study builds on this recent finding and aims at a more profound understanding of the difficulties that children with MD experience with telling time. Therefore, clock reading abilities of 154 children with MD were compared to the abilities of 571 average achieving children, and a qualitative error analysis was performed. The results of this study confirm the earlier findings of Andersson that children with MD perform worse on clock reading than average achieving children and also show that children with MD especially struggle with the combination of procedural and retrieval strategies that are needed to read complex 5-min and 1-min clock times. Children with MD make more errors, which reflects immature counting strategies and deficits in memory retrieval. This finding is in line with Geary's theory of subtypes in MD, which argues that children with MD have problems with mathematical procedures and semantic memory retrieval. (Contains 4 tables.)