round is available since version 1.0.
Prototype:
number round(number val [, number precision=0])
Parameters
	
		
			val
		
		
			the value to be rounded
		
	 
	
 
Description:
Get the rounded value of val to specified precision (number of digits after the decimal point). precision can also be negative or zero (default). 
Return value:
Returns the rounded value of val to specified precision (number of digits after the decimal point). precision can also be negative or zero (default). 
Example
echo round(3.4);         // 3
echo round(3.5);         // 4
echo round(3.6);         // 4
echo round(3.6, 0);      // 4
echo round(1.95583, 2);  // 1.96
echo round(1241757, -3); // 1242000
echo round(5.045, 2);    // 5.05
echo round(5.055, 2);    // 5.06