I expect someone more knowledgeable will come along in a moment, but I would say it depends on what you want to do with this value. If you own shares then you can check the current price with e.g. your broker or a high street bank. The value may fluctuate throughout the day, it is not a fixed thing, it depends on whether the stock exchange is open and whether these shares are being traded. If you buy or sell shares there is commission and (potentially) tax to pay, so you won't get the full market value of those shares when you sell and you will have extra to pay on top if you buy.
While you own them, the value of the shares as an asset is what it is on any given day. As at 4.26pm today the values are:
1 Lloyds Bank share is 62.81p Sterling.
1 SSE share is 1562.00p Sterling.
1 National Grid share is 949.5p Sterling.
OH says these are 'spot prices' i.e. prices current only at a specific time, and may change again today, but probably not by much. OH uses a phone App for an android phone from the Google Playstore called 'My Stocks Portfolio'. He loads the details of specific shares into the App and can then track their value, and read market news about them.