Hi 
BP shares currently trade for around £5 (see Google Finance for example), I’m guessing that you’ve seen the share price published elsewhere e.g. Google Finance, in pence so 555.50
but this translates to £5.55 in normal money
the prices displayed by different sources may be different because our prices aren’t always live & are ‘indicative’ - see the bottom of the stock’s page in the app for details
I hope that helps 