Self-efficacy refers to the belief in one’s ability to perform a task and to attain a goal It is a strong predictor of the level of motivation and persistency for a task, and of ultimate task performance A strong self-efficacy in computing, especially one that is established at an early age, contributes significantly to students’ motivations to continue work in the field One effective way of creating a strong sense of self-efficacy is to let students learn how to overcome difficulties through the experience of failures, but in a supportive and low risk setting We designed a High-Challenge and Low-Stakes principle that aims to help elementary-aged students establish an early computing self-efficacy Our approach is applied to a co-ed introductory computing program for 3rd-5th graders The qualitative and quantitative evaluation results indicate that the program is equally beneficial to students regardless of their gender in improving their computing knowledge and attitude.