Calculate the total number of sales in North America.
total number of sales = MULTIPLY(SUM(num_sales), 100000); North America refers to region_name = 'North America';
SELECT SUM(T2.num_sales) * 100000 AS nums FROM region AS T1 INNER JOIN region_sales AS T2 ON T1.id = T2.region_id WHERE T1.region_name = 'North America'