Definition:
six is a cardinal number (or 'counting number') used to indicate quantity or size. It follows the number five, and is preceded by the number seven.
Rules:
it can refer to the numeral itself, or to any group, set, or sequence that consists of six items. For example, it is used to refer to a six-sided shape (also known as a 'hexagon'), six packs of beer, or the number of six consecutive days in a week.
Examples:
1. I ordered a six pack of beer.
2. The snowflake had six different points.
3. I am going to work six days this week.