Source: https://www.tofugu.com/japanese/counting-in-japanese/

Numbers Kanji Japanese Daiji (New) Japanese Daiji (Old)
0
1 壹、弌
2 貳、貮
3 參、弎
4
5
6
7 漆、質
8
9
10
20 廿、卄 弐拾 貳拾
30 卅、丗 参拾
40
100 陌、佰
1,000 阡、仟
1,0000