To count it's simple from 11 you have to multiply and for units you have to add, for example:

十二 (10 + 2 = 12)

三十二(3 * 10 + 2 = 32)

万四 (9 * 100 + 3 * 10 + 2 = 932)

万四 (10,000 + 5 = 10 005)

from 万 we reuse the numbers from before to multiply them to 万

十二万 (120,000)

The 万 having 4 zeros the Japanese separate numbers into groups of 4

十二万 九百三十二 (120 932)