This study aimed to combine the use of electronic technology and dynamic testing to overcome the limitations of conventional static testing, and adapt more closely to children's individual needs. We investigated the effects of a newly developed computerized series completion test using a dynamic testing approach and its relation to school achievement. The study utilized a pre-test-training post-test control-group design in which 164 children from grade 2 participated. To evaluate the additional effects of dynamic testing beyond the effects of (repeated) static testing of inductive reasoning on a tablet, half of the children were trained using a graduated prompts method, while the other half of the children only practiced solving the series completion task-items. The results showed that training with graduated prompts is effective in increasing the likelihood that children can solve series completion problems accurately. Furthermore, the number of prompts children needed during training, significantly predicted the performances of children on mathematics and technical reading tests. Teacher's judgments regarding their pupils' overall school performance and potential for learning, however, did not correlate significantly with the dynamic post-test score of the series completion test, which seemed to indicate that dynamic testing provides teachers with new information about the learning progress of individuals.