CSS Counter SASS

#navigation .main_menu > ul > li{
	
	/* one item */
	&:first-child:nth-last-child(1) {
		width: 100%;
		}

 	/* two items */	
	&:first-child:nth-last-child(2),
	&:first-child:nth-last-child(2) ~ li {
		width: 50%;
		}
	
	/* three items */
	&:first-child:nth-last-child(3),
	&:first-child:nth-last-child(3) ~ li {
		width: 33.3333%;
		}
		
	/* four items */
	&:first-child:nth-last-child(4),
	&:first-child:nth-last-child(4) ~ li {
		width: 25.0%;
		}
		
	/* five items */
	&:first-child:nth-last-child(5),
	&:first-child:nth-last-child(5) ~ li {
		width: 20.0%;
		}
		
	/* six items */
	&:first-child:nth-last-child(6),
	&:first-child:nth-last-child(6) ~ li {
		width: 16.0%;
		}
		
	/* seven items */
	&:first-child:nth-last-child(7),
	&:first-child:nth-last-child(7) ~ li {
		width: 14.0%;
		}	
			
	/* eight items */
	&:first-child:nth-last-child(8),
	&:first-child:nth-last-child(8) ~ li {
		width: 11.0%;
		}
				
	/* nine items */
	&:first-child:nth-last-child(9),
	&:first-child:nth-last-child(9) ~ li {
		width: 11.11111%;
		}
}