写法如下：
20-24：20 twenty、 21 twenty-one、 22 twenty-two、 23 twenty-three、 24 twenty-four
25-29：25 twenty-five、26 twenty-six、27 twenty-seven、28 twenty-eight、29 twenty-nine
30-34：30 thirty 、 31 thirty-one 、 32 thirty-two 、 33 thirty-three 、 34 thirty-four
35-39：35 thirty-five 、36 thirty-six 、37 thirty-seven 、38 thirty-eight、39 thirty-nine
40-44：40 forty、 41 forty-one、 42 forty-two、 43 forty-three 、 44 forty-four
45-49：45 forty-five、46 forty-six、47 forty-seven、48 forty-eight、49 forty-nine
扩展资料：
分数、小数和百分数的英文写法如下：
1、1/2 : one-half
2、3/4 : three-fourths
3、 1/10 : one-tenth; a tenth
4、1/100 : one-hundredth
5、1/1000 : one-thousandth
6、1/10000 : one ten-thousandth
7、100% : one hundred per cent
8、0.5% : point five per cent
9、0.46% : point four six per cent
10、2.05 : two point nought five
11、6.003 : six point nought nought three
12、78.12 : seventy-eight point one two
21 twenty-one
22 twenty-two
23 twenty-three
24 twenty-four
25 twenty-five
26 twenty-six
27 twenty-seven
28 twenty-eight
29 twenty-nine
30 thirty
31 thirty-one
32 thirty-two
33 thirty-three
34 thirty-four
35 thirty-five
36 thirty-six
37 thirty-seven
38 thirty-eight
39 thirty-nine
40 forty
41 forty-one
42 forty-two
43 forty-three
44 forty-four
45 forty-five
46 forty-six
47 forty-seven
48 forty-eight
49 forty-nine本回答被网友采纳
难得