The purpose of my examination is to investigate the importance of language to mathematics, how pupils’ language and reading comprehension influence their capacity for solving mathematical problems. My method is to let 16 pupils solving 13 mathematical problems and interviews them about 5 specifically chosen problems. The results of my examination show that language comprehension plays an important role in the work for solving mathematical problems. I can see that literature concerning this matter illustrates the same result as I prove. I also give examples of how to help pupils with these kinds of difficulties.