How can I determine the Census District, and Sub-district of a particular street address in Toronto in the 1901 Census?

The streets for 1901 census especially in Toronto are challenging, but not impossible...to this end, I have printed from Weldon Library (University of Western Ontario), the maps in the "Electoral Atlas of Canada" for major cities, which show exactly the districts of Toronto, for example and their boundaries.
  The difficulties are two-fold: 1a). Many streets no longer exist, so the use of the City Directory in the Regional Room (2nd floor) first will give a cross street for the number you need. (For example, 369 Richmond is between the streets of King and Dundas, on the west side) This info can then be looked up on a current map, and if it exists, just move to the same region on the Electoral map and look for the intersection, etc.
  If the street you have is newer than the 1901 Atlas maps, then you need to be a bit creative - again, go back to the directory and use the alpha by name part to get the then current address and try to locate it with its nearest cross street on the Atlas map.(in other words, find where they lived then by looking up their name) 1b). If you have no address, use the directory first, obviously.
  The greatest challenge is in the Toronto East versus York East and it has been my experience that MUCH is in York east....or perhaps that's just where most of mine have been. 2a). It is important to do one thing, esp. for large cities - print the matching map from the Atlas and put a pin on the map where you section of film begins. Go a few turns and put another pin onto the map and you will begin to see a pattern emerging.
  It is supposedly a clockwise block and then the next block, also clockwise, and each should begin in the north west corner of the block and proceed east, south, west and north back to the starting corner. The census taker should then walk east along the block face to the next new block and continue in the same way - east, south, west, north etc. until he has done every block If you are following the progression, you can see the pattern, usually.
  Remember to read only the addresses and if your "address" isn't in the list, skip the names that go with those addresses. (It is set up always a couple pages of addresses followed by several pages of the names that reside there and repeating.) 2b) Match the street to the ward and select the film that lists that ward (in the directory of census films) I sometimes use the 1871 and 1881 references to find the lesser units, but I always use the 1901 ref for the bigger cities. I hope this helps.
  I will gladly teach anyone who comes to the Family History Centre (London, Ontario) during my Tues. morning shifts how to do this and the maps I have printed off for major centres are all there. We have only the 1923 directory, so if their street isn't listed in it, we may be stuck. (From Forebears Research & Associates )