I, too, remember this as I was born and raised in Canada. I don't offhand recall the episodes mentioned in the earlier review, but I do remember a sort of rival kids gang to the Ten, led by one Spider McGlurk. Spider's group was always outsmarted, though in later episodes, the two groups actually worked together to solve a mystery.
I remember one episode in which the Ten (and possible McGlurk's gang) took over a submarine (!), successfully submerged it, and then surfaced to a tumultuous welcome in Sydney Harbour.
I think we tended to see a maximum of 7 of the Ten at any one time. And no girls, if memory serves.