US coastline: 12,383 miles
Canadian coastline: 113,211 miles more than US coastline
113,211 more than US coastline = 113,211 more than 12,383
113,211 more than 12,383 = 113211 + 12383
113211 + 12383 = 125594
The Canadian coastline is therefore 125,594 miles long. Hope this helps! :)