30, 30?

Forty. Forty?

Fifty-fifty?

60, 60?

70. 70?

80. 80?

the nineties

100? one hundred

Ordinal class:

Thirty, thirty?

Fortieth, 40th?

Fifty?

Sixty?

Seventy-seventh street?

August eightieth?

Ninety-nine

No. 100 1

Extended data

Radix digital memory;

Numbers from 20 to 90 all end in ty. 20 special memory, 30 and 13 are the same root 30, pay attention to the difference between 40, 50 and 4, 5.

Also note that 80 is 80. 2 1-29; The numbers of 3 1-39 ... 9 1-99 are all the same, and 1 to 9 are added after the ten digits. 100 is one hundred.

Numeric symbol of ordinal number:

The sequential English words from 1 to 100 have a simpler expression, using Arabic numerals directly. The units are 1→ 1st, 2→2, 3→3, and the rest are added with th, for example, 3 1, 43, 65.