From 0 to 10

11

The essential foundation. Memorize it — everything else follows.

líng zero
one
èr two
sān three
four
five
liù six
seven
eight
jiǔ nine
shí ten

The tens

10

Structure: number + 十. Twenty = "two-ten", thirty = "three-ten", etc.

shí 10
二十 èr shí 20 (two × ten)
三十 sān shí 30
四十 sì shí 40
五十 wǔ shí 50
六十 liù shí 60
七十 qī shí 70
八十 bā shí 80
九十 jiǔ shí 90
一百 yī bǎi 100 (百 = hundred)

Building compound numbers

10

For 11-99: tens + units. Forty-two = 四十二 (four-ten-two). No exceptions.

十一 shí yī 11 (ten-one)
十五 shí wǔ 15
二十一 èr shí yī 21 (two-ten-one)
三十三 sān shí sān 33
四十二 sì shí èr 42
五十五 wǔ shí wǔ 55
六十八 liù shí bā 68
七十七 qī shí qī 77
八十九 bā shí jiǔ 89
九十九 jiǔ shí jiǔ 99