To start, drag out a math block (set to subtract) and a variable block. Both are found under the red data operations tab of the programming palate:
A variable is a placeholder for a value. They have two operations: write, which changes the value stored in the variable, and read, which retrieves the stored value. This means that variables are a convenient way to save a value in one part of a program to use it in another part of the code. In the EV3 software, variables can store three types of data: numeric, logic, and text.
A variable must be defined before we can use it in the program. The first step is to choose the data type. By ...
