Php 7.1 / 7.2 rain error

Hi everyone,
if I set the php of the 7.1 or 7.2 server, the rain goes into error.
When the forecast marks: 0.2, 0.3 etc. always with the 0 in front, the following example is out: 0.23333337
if I leave php 7.0 everything works correctly, that is, it marks 0.2 mm
surely it’s a php problem of the file, who can help me solve it?
https://www.meteosantangelo.it/wxsim1/forecast.php

Thank you