Template:Round/doc

This templates rounds parameter 1 to the number of digits after the point optionally given as parameter 2. If parameter 2 is negative, rounding is to a multiple of 10. If parameter 2 is undefined, numbers with 4 digits before the point are rounded to integers, numbers with 3 digits before the point are rounded to 1 digit after the point, numbers with 2 digits before the point are rounded to 2 digits after the point, and numbers with 1 digit before the point or none are rounded to 3 digits after the point.

In other words, if parameter 2 is undefined, rounding is to 4 significant digits, except that it is not cruder than rounding to an integer and not finer than rounding to three digits after the decimal point.

Examples:



Note that trailing zeros are not shown, so rounding can seem cruder than has actually been applied:

While this is a limitation of the template (normally there would be trailing zeros to show the precision), there is also the general problem that if a number is an integer with trailing zeros, then the precision is not clear:

TemplateData
{	"params": { "1": {			"label": "Value", "description": "The value to be rounded", "example": "3.14159265", "type": "number", "required": true },		"2": {			"label": "Number of digits", "description": "Number of digits after the point. If negative, rounding is to a multiple of 10. If undefined, numbers with 4 digits before the point are rounded to integers, numbers with 3 digits before the point are rounded to 1 digit after the point, numbers with 2 digits before the point are rounded to 2 digits after the point, and numbers with 1 digit before the point or none are rounded to 3 digits after the point.", "example": "2", "type": "number" }	},	"description": "This templates rounds a value to the optionally given number of digits after the point. " }