CREATE TABLE table_57396 ("Rank" FLOAT, "Nation" TEXT, "Gold" FLOAT, "Silver" FLOAT, "Bronze" FLOAT, "Total" FLOAT)

What is the number of bronze for Canada and silver is less than 0?
SELECT SUM("Bronze") FROM table_57396 WHERE "Nation" = 'canada' AND "Silver" < '0'
SELECT SUM("Bronze") FROM "table_57396" WHERE "Nation" = 'canada' AND "Silver" < '0'