Final answer:
Approximately 600,000 Canadians served in the First World War, experiencing significant societal changes and contributing to the massive military force necessitated by the conflict.
Step-by-step explanation:
Approximately 600,000 Canadians served in the First World War. The joy and relief that came with the signing of the Armistice were overshadowed by the sacrifices endured, including 60,000 lives lost. World War I also led to significant shifts in Canadian society, offering a stark contrast to the life known before the war began. Furthermore, the need for a large military force led to the controversial implementation of conscription in Canada. Despite the social upheaval and the initial small voluntary military force, Canada's involvement grew substantially by the war's end.