three; 3
「参」 has another reading with different meanings.
Chinese "Three Stars" constellation (one of the 28 mansions)
参の数字を書いてね。
Write the number three.
参つの箱を持ってきた。
I brought three boxes.
書類には金額を参万円と記入してください。
Please enter the amount as thirty thousand yen on the form.