Kachi, H.; Yasunaga, T.; Sakai, K.; Hyuga, R.; Shiota, S. DEVELOPMENT AND EVALUATION OF MATERIALS FOR CHILDREN TO REDUCE THE TABLET DEVICE OPERATIONAL PROBLEMS: Received: 10th January 2022; Revised: 14th February 2022, 3rd March 2022, 5th March 2022; Accepted: 7th March 2022. pijtel 2022, 6, 271-284.