The numbers one to ten
一 yī (1), 二 èr (2), 三 sān (3), 四 sì (4), 五 wǔ (5), 六 liù (6), 七 qī (7), 八 bā (8), 九 jiǔ (9), 十 shí (10).
A good order to learn them
Start with 一, 二 and 三: they are one, two and three horizontal strokes, so kids get an early win. Then 十, 八 and 六, which are short. Leave 四, 五 and 九 for later, as their stroke order is less obvious.
Counting beyond ten
Once kids know 一 to 十 they can write every number to 99: 十一 is 11, 二十 is 20, 九十九 is 99.