# Chapter 3 - Summary¶

Chapter 3 included the following concepts from computing.

• Arithmetic Expression - An arithmetic expression contains a mathematical operator like `-` for subtraction or `*` for multiplication.

• Assignment - Assignment means setting a variable’s value. For example, `x = 5` assigns the value of 5 to a variable called `x`.

• Assignment Dyslexia - Assignment Dyslexia is putting the variable name on the right and the value on the left as in `5 = x`. This is not a legal statement.

• Camel-Case - Camel-case is when the first letter of each additional word is uppercased when you create variable names that have several words in them like `firstName`.

• Integer Division - Integer division is when you divide one integer by another. In some languages this will only give you an integer result, but in Python 3 it returns a decimal value.

• Mixed-Case - Mixed-case means using upper and lower case letters in a variable name like `"HI There"`. One way to do this is to use camel-case.

• Modulo - The modulo, or remainder operator, `%`, returns the remainder after you divide one value by another. For example the remainder of `3 % 2` is 1 since 2 goes into 3 one time with a remainder of 1.

• Tracing - Tracing a program means keeping track of the variables in the program and how their values change as the statements are executed. We used a Code Lens tool to do this in this chapter.

• Variable - A variable is a name associated with computer memory that can hold a value and that value can change or vary. One example of a variable is the score in a game.

Note

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