What is the average number of sales in Japan?
in Japan refers to region_name = 'Japan'; average number of sales = multiply(avg(num_sales), 100000) where region_name = 'Japan'
SELECT AVG(T2.num_sales) * 100000 AS avg_japan FROM region AS T1 INNER JOIN region_sales AS T2 ON T1.id = T2.region_id WHERE T1.region_name = 'Japan'