Use the [var statement](/reference/variables/var) and the [assignment operator](/reference/variables/assign) declare a *local* number variable. Like this:
The [show number](/reference/basic/show-number) function displays a number on the [LED screen](/device/screen). For example, this code displays the number 42:
Some functions return a number, which you can store in a variable. For example the following code gets the display brightness (using the [brightness function](/reference/led/brightness)) and stores the value in a variable named `brightness`:
The [math library](/reference/math) includes math related functions. In the [Block Editor](/blocks/editor), click `math` on the Code Keyboard to see the math functions. For example, the `absolute` function returns the returns the absolute value of input parameter `x`: