As covid 19 continuous spreading in many countries. There were serious problem appeared, not only for human health but also for education. For that reason, Teachers should implemented online learning strategies to enhance the activities of learning process. This article elaborates design of classroom activities of teachers by using online learning resources for mathematics class. Subject of this study were teachers of elementary school in Kranggan Mojokerto. Data were collected by online questioner and online task. Quantitative and qualitative results are discussed along with teachers performance in designing classroom activities. The study highlighted the need of designing online classroom abilities for teacher to teach 21st century student.