How many? It's hard to figure it out.

http://thetyee.ca/News/2008/04/08/CountingHomeless/

This is a link to an article written by a volunteer of the Social Planning and Research Council of BC (SPARC), who organize a group of volunteers who try to count the homeless on behalf of the Metro Vancouver Regional Steering Committee on Homelessness.

Accuracy is hard to come by in this endeavor. One thing people seem to agree on though, is that the homeless are consistently under-counted.