Procedures support modularity in developing programs. Parameters can provide greater flexibility, reusability, and efficient use of resources. Students create procedures and/or functions that are used multiple times within a program to repeat groups of instructions. They generalize the procedures and/or functions by defining parameters that generate different outputs for a wide range of inputs. For example, students could create a procedure to draw a circle which involves many instructions, but all of them can be invoked with one instruction, such as “drawCircle.” By adding a radius parameter, students can easily draw circles of different sizes. (CA CCSS for Mathematics 7.G.4) Alternatively, calculating the area of a regular polygon requires multiple steps. Students could write a function that accepts the number and length of the sides as parameters and then calculates the area of the polygon. This function can then be re-used inside any program to calculate the area of a regular polygon. (CA CCSS for Mathematics 6.G.1)