The shell bone script for character Two is
The shell bone script for character Three is
They are indicative characters.
There was story long time ago. A rich man had a young boy, he sent his son to learn Chinese from a private teacher. The first day, teacher told kids "One is one horizontal stroke". The second day, the teacher told kids "Two is two horizontal strokes". The third day, the teacher told kids "Three is three horizontal strokes". The boy refused to go teacher's home in fourth day, he told his father:"it is too easy, I have known all of them". The father was proud of his smart son.
One day, the father invited some friends for dinner. The father mentioned his smart son to the guests. One guest asked if I could ask him to write my family name? The father passed the request to his son. The little boy asked the guest "What is your family name?". The guest said "Ten Thousand". The Chinese character for Ten Thousand was "萬“ (traditional Chinese). But the boy didn't know. So he drew the strokes, one, two, three, four, five, ........
After half hour, the guest asked the boy :"Are you done?", the boy said "No". One hour passed, the guest asked "Are you done?", the boy answered "No". The guest asked "Why do you take so long?",
the boy complained "Why do you have so big name?!".
Probably they are so simple, there are no small seal scripts for One and Two, only three, which is same as its shell bone script.
The clerical scripts for the three characters are
The current standard printing scripts are
The pinyin for them are "Yi1", "Er4", "San1".
let's see the small seal script for the three characters