Learning numbers in Japanese is not difficult at all. The Japanese numerals are the number names used in Japanese. In writing, they are the same as the Chinese numerals, and the grouping of large numbers follows the Chinese tradition of grouping by 10,000. Two pronunciations are used: the Sino-Japanese (on’yomi) readings of the Chinese characters and the Japanese Yamato kotoba (native words, kun’yomi readings).
There are two ways of writing the numbers in Japanese: in Arabic numerals (1, 2, 3) or in Chinese numerals (一, 二, 三). The Arabic numerals are more often used in horizontal writing, and the Chinese numerals are more common in vertical writing.
The Japanese number system has two sets of numbers: the Sino-Japanese numbers and the Native Japanese numbers.
The most common Japanese numbers are the Sino-Japanese numbers. But you will often come across 1 – 10 in Native Japanese numbers.