Numbering System

 In the Japanese number system, numbers are grouped in sets of four digits, similar to the Western system, where numbers are grouped in sets of three digits. Here are the basic building blocks of the Japanese number system:

1: 一 (ichi)

2: 二 (ni)

3: 三 (san)

4: 四 (shi or yon)

5: 五 (go)

6: 六 (roku)

7: 七 (shichi or nana)

8: 八 (hachi)

9: 九 (kyuu or ku)

To express numbers in Japanese, you combine these building blocks, as well as the following counters:

10: 十 (juu)

100: 百 (hyaku)

1000: 千 (sen)

10,000: 万 (man)

To count from 1 to 100 in Japanese, you use the following numbers:

1: 一 (ichi)

2: 二 (ni)

3: 三 (san)

4: 四 (shi or yon)

5: 五 (go)

6: 六 (roku)

7: 七 (shichi or nana)

8: 八 (hachi)

9: 九 (kyuu or ku)

10: 十 (juu)

20: 二十 (nijuu)

30: 三十 (sanjuu)

40: 四十 (yonjuu)

50: 五十 (gojuu)

60: 六十 (rokujuu)

70: 七十 (shichijuu or nanajuu)

80: 八十 (hachijuu)

90: 九十 (kyuujuu)

100: 百 (hyaku)

To count from 101 to 199, you use "hyaku" (100) as the counter, followed by the number from 1 to 99. For example, 101 is "hyaku ichi" (100 + 1), 102 is "hyaku ni" (100 + 2), and so on.

To count from 200 to 999, you use the numbers from 2 to 9 as the first counter, followed by "hyaku" (100), and then the numbers from 1 to 99 as the second counter. For example, 243 is "ni-hyaku yon-juu san" (2 x 100 + 40 + 3).

When counting from 1000 to 9999, you use "sen" (1000) as the counter, followed by the numbers from 1 to 999. For example, 1000 is "sen", 2567 is "ni-sen go-hyaku roku-juu nana" (2 x 1000 + 5 x 100 + 60 + 7), and so on.

There are some special cases where "sen" (1000) is pronounced as "issen", "ni-sen" (2000) is pronounced as "nissen", and "san-sen" (3000) is pronounced as "sanzen". Similarly, "man" (10,000) is sometimes pronounced as "ichiman" (one ten thousand), especially when used as a counter.

To count from 10,000 to 99,999, you use the numbers from 1 to 9 as the first counter, followed by "man" (10,000), and then the numbers from 1 to 9999 as the second counter. For example, 20,000 is "ni-man", 76,543 is "nana-man roku-sen go-hyaku yon-juu san" (7 x 10,000 + 6 x 1000 + 5 x 100 + 40 + 3), and so on.

To express numbers larger than 100,000, you can use the Sino-Japanese counting system, which is based on Chinese characters and is used for larger numbers. For example, "hyaku-man" (100,000) can be written as "百万", and "juu-man" (1,000,000) can be written as "千万".

To express numbers larger than 1,000,000, you can use the following counters:

一億 (ichioku or 10^8): 100,000,000

十億 (juuoku or 10^9): 1,000,000,000

百億 (hyakuoku or 10^10): 10,000,000,000

一兆 (icchou or 10^12): 1,000,000,000,000

十兆 (juuchou or 10^13): 10,000,000,000,000, and so on.