floor function:

If the argument is numeric, return it's floor.

Examples:

• running: (floor 10.3) will give: 10

• running: (floor -10.3) will give: -11

• running: (floor -10) will give: -10

• running: (floor -10.5) will give: -11

• running: (floor 10.99) will give: 10

• running: (floor [0]) will return nothing