Highly and Minimally Guided Discovery Instruction for Basic Add-1 and Doubles Combinations

This study evaluated computer-based interventions designed to promote fluency with basic addition combinations (add-1 and doubles) among kindergarten through second-grade students. The interventions used either highly guided discovery learning (which sequentially arranged problems to highlight patterns and provided explanatory feedback) or minimally guided practice (semi-random practice with feedback on correctness only). The highly guided add-1 training connected adding 1 to number-after relations, while the highly guided doubles training connected doubles to everyday analogies and even numbers. Students participated in two 30-minute computer sessions per week over approximately 9 months. The interventions included preparatory training (7 sessions on concrete counting strategies and 8 sessions on estimation) followed by three stages of primary training focused on strategy discovery, practice, and fluency development. All training was delivered one-on-one at computer stations outside classrooms.