This paper examines the limited proficiency to engage in programming algorithms among university students in information technology and information system in several universities across Surabaya, Indonesia. The purpose of this research is to find the most influential factor in learning programming algorithm using a quantitative approach. The research subjects were second-semester information technology students in several private universities in Surabaya, Indonesia. The research instruments were mathematical reasoning and basic algorithm programming test. Mathematical reasoning tests incorporated linear algebraic, basic calculus, and mathematical logic. The data analysis used was variant-based Structural Equation Modelling, also known as Partial Least Squares - Structural Equation Modelling based on Smart-PLS 3. With [alpha] = 5%, the research results conclude that mathematical reasoning positively influences algorithm programming ability with an R score of 0.999, and that the most influential variable among mathematical reasoning abilities was algebra with an R score of 0.732.