A check of the 1901 British Census finds the family of Harris Dancyger living at 35 Scarborough Street in Whitechapel.
From this census we find that Harris age 48, is a Jewish Minister from Russia. His wife, Jane is also 48 and is herself from Russia. From the census we find that there are 7 children still living at home at the time of the census. In addition to the family of Harris we find three other families of the same surname. While the name is not a common one and they are most likely all related, the census just doesn't give us enough information to know for sure.
There is however a great source for this time frame. In 2004, Miriam Pollak released her great work on the Jewish Chronicle of London. That work, The Jewish Chronicle Project; Personal Announcements 1900-1909 (FHL CD#2697) is a must for those researching England families at the turn of the twentieth century. In searching the database for the surname Dancyger, we get 6 hits. Of those hits, one adds a great deal of information to what we already know. It says:
Death 28 Oct 1904
The records of the Dancyger family can be found in the Jews of the British Isles.