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Great job! In this lesson, we learned all about using numbers in PHP. Let’s review what we covered:

• PHP has two number data types: integers and floating point numbers
• We can use arithmetic operators for performing math operations:
Operation: Example:
Addition `+` `echo 1 + 4.5; // Prints: 5.5`
Subtraction `-` `echo 9 - 1; // Prints: 8`
Multiplication `*` `echo -1.9 * 2.9; // Prints: -5.51`
Division `/` `echo 9 / 1; // Prints: 9`
Modulo `%` `echo 11 % 3; // Prints: 2`
Exponentiation `**` `echo 8**2; // Prints: 64`

• Operations have an order of precedence meaning that certain types of operations in a chain will be evaluated before others: first evaluated will be any operation wrapped in parenthesis (`()`), next exponents (`**`), then multiplication (`*`) and division (`/`), and finally addition (`+`) and subtraction (`-`). The acronym PEMDAS can be a helpful way of remembering the order.
• We can assign number values to variables and then perform numerical operations with them.
• We can use mathematical assignment operators as a shorthand when reassigning number variables:
Operation: Long Syntax: Short Syntax:
Add \$x = \$x + \$y \$x += \$y
Subtract \$x = \$x - \$y \$x -= \$y
Multiply \$x = \$x * \$y \$x *= \$y
Divide \$x = \$x / \$y \$x /= \$y
Mod \$x = \$x % \$y \$x %= \$y