Lottery, Public Lottery, Lottery Ticket
noun
宝 is a treasure. くじ is a lottery. So if you have a treasure lottery (you win treasure if you win the lottery) then you have yourself a lottery.
たからくじ
The reading uses the 宝 vocab reading, たから.
宝くじはインターネットで手に入ります。
The lottery is available on the Internet.
「妹が宝くじに当たったのよ。」「すごいね！で、いくら？」「一万円。」
"My sister won the lottery." "That's amazing! How much?" "10,000 yen."
百万円の宝くじが当たった山下先生。次の日からクラスに来なくなった。
Yamashita-sensei had won a million yen lottery. He stopped coming to class the next day.