In recent years it has become increasingly clear what meaning language has for the acquisition of professional competences and what relevance a continuous language promotion has in all school subjects. This was the starting point for the BiSS funding program, which implemented language support at various schools in schools across Germany, and which was to be evaluated through accompanying research. One such evaluation project was the EvaFa project. This examined the mathematics-specific language support of schools from the BiSS program. Accordingly, the present article deals with the question of to what extent students who take part in language-promoting mathematics lessons benefit from language support from one year and have higher levels of text comprehension or a larger vocabulary. For this purpose, the longitudinally collected student data from eight classes, which formed a thematically homogeneous language support cluster, were analyzed as part of a pre-post design (including socio-demographic background characteristics, language skills, the availability of technical words, mathematical competence, understanding of word problems and the assessment of teaching aspects). The analysis of the sample (133 pupils in the 5th and 6th grades) shows that pupils perceive different teaching aspects in a very differentiated manner and are quite sensitive to changes in the teaching of mathematics. In addition, the mathematical understanding of word problems shows significant increases between the two measurement times in the funding period.