Panggabean, F.T.M., Puspa Olivia Pardede, Rizky Mauli Dini Sitorus, Yani Kartini Situmorang, Evan S Naibaho and Juan Samuel Simanjuntak 2021. Application of 21st Century Learning Skills Oriented Digital-Age Literacy to Improve Student Literacy HOTS in Science Learning in Class IX SMP. Jurnal Mantik. 5, 3 (Nov. 2021), 1992-1930.