Can we convert a number field input into monetary format?

is there a way to require a number field to force money formatting? i.e. 2 decimal places?

With a number field it would not be possible to force decimal places.  It would require passing the value entered in the number field to a calculation field. 

https://www.jotform.com/help/259-How-to-Perform-Form-Calculation-Using-a-Widget

The calculation field would need show empty decimal places enabled:

Here is a quick example form to show how it would work:

https://form.jotform.com/81155775421962