This version is out of date, covering development from v5.0.0 to v5.12.2. It is maintained here only for inbound reference links from elsewhere.

Jump to the current version of aTbRef.

Tinderbox Icon


Operator Type: 

Operator Scope of Action: 

Operator Purpose: 

Operator First Added: 

Operator Altered: 

 Function   [other Function type actions]

 Item   [operators of similar scope]

 Formatting   [other Formatting operators]




This function makes it easier to format numbers. The function returns the associated Number-type attributes value rounded to N decimal places. If $MyNumber is 268.3289 then:


…sets $MyNumber to 268.33, whilst:

$SomeNumber = $MyNumber.precision(2) 

…sets $OtherNumber to 268.33. The above examples are the equivalent of the older syntax using format():


Literal numbers, e.g. 3.1415927, can also be worked with:

5.1415927.precision(2) is 5.14

The above works but the following syntax may seem less ambiguous by using parentheses to delimit the literal number:

(5.1415927).precision(2) is 5.14

Since Number.precision() was added, format() has been supplemented by a Number.format(). The latter, in single input version equates to Number.precision().

The .precision() function can be used to add trailing zeroes to a decimal. If $MyNumber is 214.40, it will display as 214.4 which can be unhelpful if this actually represents £214.40. $MyNumber.precision(2) will return 214.40 but be careful about under-the-hood number/string coercion such as can happen in contexts like $DisplayExpression.

$MyOtherNumber = $MyNumber.precision(2) gives 214.4

$MyString = $MyNumber.precision(2) gives "214.40"

In a $DisplayExpression:

$MyNumber.precision(2) gives "214.40"

$Name+" : "+$MyNumber.precision(2) gives "214.40"

$Name+ " : " + sum(children,$MyNumber).precision(2) 

It may still be easier to use format() as no extra parentheses are required:

$Name+ " : " + format(sum(children,$MyNumber),2) 

Possible relevant notes (via "Similar Notes" feature):

A Tinderbox Reference File : Actions & Rules : Operators : Full Operator List : Number.precision(N)