Calculators are widely used in mathematics education, yet limited research examines the effects of calculators for students with mild intellectual disability. An alternating treatments design was used to study the effects of calculator types (i.e., scientific and graphing) on the mathematical performance (i.e., computation and word problems) of five fifth-grade students with mild intellectual disability. Both types of calculators were effective in increasing the accuracy and efficiency of the mathematical performance of all five students. Results support the use of calculators for students with mild intellectual disability when working on computation and word problem-solving questions.