On January $1,2021,$ Wilke Corp. had $480,000$ shares of common stock outstanding. During $2021,$ it had the following transactions that affected the Common Stock account.

February $1$ Issued $120,000$ shares

March $1$ Issued a $10\%$ stock dividend

May $1$ Acquired $100,000$ shares of treasury stock

June $1$ Issued a $3-$for$-1$ stock split

October $1$ Reissued $60,000$ shares of treasury stock

$($a$)$

Determine the weighted$-$average number of shares outstanding as of December $31,2021.$

The weighted$-$average number of shares outstanding