In the Trnjanska experimental primary school the first round of experiments on computer supported mobile collaborative learning (mCSCL) was conducted. Between December 2016 and February 2017 the students used software developed in the SCOLLAm project to solve mathematical problems (addition and subtraction) for 1st and 2nd grades of primary school. Tablets scaffolded face-to-face discussions about possible solutions and helped students to agree on correct solutions.