Despite numerous efforts since the results of the first PISA studies to support children's reading skills from the first grade onwards, around 14% of a cohort still achieve only basic reading skills at the lowest competency level. According to scientific studies, specific difficulties with reading fluency at the sentence and text level are linked to negative impacts on reading comprehension. Building on the training program for rapid word recognition, which focuses on isolated word recognition, ProSL helps struggling elementary school children transfer their ability to quickly recognize individual words to the sentence and text level. The children become familiar with particularly common word parts in sentences and short stories during the exercises.