The lesson that introduces these numbers is Lesson 5 – Numbers, months and days.
| 0 | 零 | líng |
| 1 | 一 | yī |
| 2 | 二 | èr |
| 3 | 三 | sān |
| 4 | 四 | sì |
| 5 | 五 | wǔ |
| 6 | 六 | liù |
| 7 | 七 | qī |
| 8 | 八 | bā |
| 9 | 九 | jiǔ |
| 10 | 十 | shí |
| 11 | 十一 | shí yī |
| 12 | 十二 | shí èr |
| 13 | 十三 | shí sān |
| 14 | 十四 | shí sì |
| 15 | 十五 | shí wǔ |
| 16 | 十六 | shí liù |
| 17 | 十七 | shí qī |
| 18 | 十八 | shí bā |
| 19 | 十九 | shí jiǔ |
| 20 | 二十 | èr shí |
| 99 | 九十九 | jiǔ shí jiǔ |
| 100 | 一百 | yī bǎi |
Note
All numbers higher than twenty follow this formula: A × “十” (shí) + B. In this formula, you multiply A by ten (“十”) and then add B to the product. This means 21 would be: 二十一 (which is literally “two-ten-one”).