“…The formula was used to calculate the percentage of trial results follows equation ( 3) (Dalimunte & Salmiah, 2019;Ginting, 2018;Sari & Rezeki, 2019;Sutirna, 2019), while the standard percentage of the quality level of material contents following the range of the score of percentage quality. The percentage score in the range of 0 to 54 is mean poor, the percentage score in the range of 55 to 64 is mean less, the percentage score in the range of 65 to 79 is mean moderate, the percentage score in the range of 80 to 89 is mean good, and the percentage score in the range of 90 to 100 is mean excellent (Mantasiah, Yusri & Jufri, 2020;Nawawi, Nizkon & Azhari, 2020;Sitorus, 2017;Sugiharni, 2018;Yulina, Permanasari, Hernani & Setiawan, 2019).…”