“…Many previous studies using CTL, can improve the students' abilities. The results of the research included the influence of mathematical communication skills, self-confidence, and mathematics learning achievement of junior high school students (Agustyaningrum & Widjajanti, 2013), increasing the activeness and learning outcomes of mathematics (Taurina & Wasitohadi, 2015;Yeliherti, 2015), learning achievement and affective aspects better than direct learning models (Negara, K, & Sujadi, 2016), improving learning outcomes in mathematics, science and social studies (Hutama, 2014;Jusmaini, 2016;Khoiriyah, Laili, & Mahmudah, 2018;Murniati, 2016;Mustamu, 2018 ;Qisthy, Sukardi, & Tarmudji, 2012;Ruskandi & Ferdian, 2015;A. Wijayanti & Wulandari, 2016;Yulindaria & Cahyani, 2017), improving student achievement (Padri, Utari, Nurhidayah, & Permatasari, 2012), communication skills student mathematics (Yuliani, 2015), increasing students' self-confidence in mathematics (Ibrahim, 2018), improving the quality of mathematics learning (Yenti, 2009), improving problem solving skills (Rofik, 2 015), improving understanding of concepts (Fatmasari, Zainuddin, & An'nur, 2013;Fitria, Sumarni, & Wusqo, 2016;Hutabarat, 2016), there is a positive and significant relationship between mathematical communication skills and self-esteem both using learning with the CTL approach (Yuniarti, Sulasmini, Rahmadhani, Rohaeti, & Fitriani, 2018), improving writing skills (Kristiyani, 2009), improving quality of learning outcomes (Pukjiwati, 2017), improve critical thinking skills in learning Chemistry and Social Sciences (Ruskandi & Ferdian, 2015;Tantu, 2018), have a positive effect and improve high-level thinking skills (Fayakun & Joko, 2015), affect learning outcomes cognitive and scientific attitudes of students (Cholifah, Parmin, & Dewi, 2016).…”