Small White Butterflies

Today it is not quite as hot as it has been for the last two days and there is a little breeze, although not everyone will agree with me, this is a much better temperature.
 
On my walk around the garden this afternoon, accompanied by my husband as well as Dougal and Florence, I saw at least twelve white butterflies on this old Willow stump. Before I could take a picture, Florence decided to investigate and they all flew away.
 
Although I waited for them to resettle, only six were on the tree stump at any one time, so these are my blip for today. They are called ‘Small White’, (Pieris rapae); their common name, along with the ‘Large White’ is Cabbage White.  Looking at the underside these all appear to be male, (please correct me if I am wrong,) but the underside of the female white butterflies are, I think,  yellower than these.
   
 
First Update: Many thanks to Mollyblobs for identifying these, as Small Whites and Green-Veined Whites; please see her comment below.

Second Update: Thanks to Orchid99 for posting a link to the Big Butterfly County 2016. I have added mine, if you want to join in, this is the link.