❶ 基数と序数
基数
1
one
2
two
3
three
4
four
5
five
6
six
7
seven
8
eight
9
nine
10
ten
11
eleven
12
twelve
13
thirteen
14
fourteen
15
fifteen
16
sixteen
17
seventeen
18
eighteen
19
nineteen
20
twenty
序数
1st
first
2nd
second
3rd
third
4th
fourth
5th
fifth
6th
sixth
7th
seventh
8th
eighth
9th
ninth
10th
tenth
11th
eleventh
12th
twelfth
13th
thirteenth
14th
fourteenth
15th
fifteenth
16th
sixteenth
17th
seventeenth
18th
eighteenth
19th
nineteenth
20th
twentieth
❷ 大きな数字
30
thirty
40
forty
50
fifty
60
sixty
70
seventy
80
eighty
90
ninety
100
a [one] hundred
101
a [one] hundred (and) one
1,000
a [one] thousand
1,234
one thousand two hundred (and) thirty-four
10,000
ten thousand
100,000
a [one] hundred thousand
1,000,000
a [one] million
10,000,000
ten million
100,000,000
a [one] hundred million
1,000,000,
a [one] billion
❸ 年号の読み方 普通は2000年までは2つに区切って読みます。
645
six forty-five
1192
eleven ninety-two
2000
the year two thousand
2025
twenty twenty-five / two thousand and twenty-five
❹ 日付の読み方 日にちは序数で表します。
4月6日
April 6th
9月1日
September 1st
12月24日
December 24th
❺ 小数点（point）
3.1415
three point one four one five
❻ 分数 分子は基数，分母は序数を用いて表します。
1
2
2
a [one] half
1
3
3
a [one] third
1
4
4
a [one] quarter / a fourth
3
10
10
three tenths