I have 2 problems

In an input field called “miles of drive”, I calculated the distance between 2 addresses using the searchbox starting & ending values. It results in a never ending decimal eg 12.436323765947569 miles. I only want 2 decimal places as a result eg. 12.44 miles. I have set the content format to decimal and the decimal place to 2…yet it still results in the never ending decimal number.

I am trying to use math.js to calculate a formula using this decimal number, however, when i add this input field “miles of drive” into the equation, it results back in a blank result. When i take this input field OUT of the equation, the equation works.
What do I have to do to get this input field be able to be multiplied by other input fields? do i have to set a formatting to something? I cannot figure it out…