# 3.9. 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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