The purpose of this study was to investigate what kind of experience teachers have in working with manipulatives in mathematics to strenghten the number sense of primary school pupils, with or without mathematics difficulties. Number sense is fundamental in mathematics and the early development of the number sense can be an indication of the pupil´s future performance. The results are based on interviews, which were processed based on content analysis, of eight teachers who all are licensed teachers and are presented based on four catagories and nine sub-catagories. The results show that the teachers use manipulatives in their teaching, and they have experience that the manipulatives strenghten the pupils number sense.