Hi Nibblenic welcome & well done on your loss so far
you would need to look on the box to see how many calories are in the entire egg (I did this last week for a smarties egg & it was about 600 kcals!!!)
then if you broke the egg into 10 pieces (so 60 kcals each) it would be 3 syns per piece (1 syn = 20 kcals) approx 30 syns for the entire egg
so if you are struggling to use your syns on anything else, you could eat the whole thing over 2 days guilt free
hope this helps xx