Understanding how to write Japanese numbers should take very little time and effort to learn. Understanding how to write Japanese numbers is really that simple to learn. Only takes an hour or two to fully memorizes the Japanese number system.
Japanese Numbers are written from Left to Right.
You basically write the Japanese Characters in order. If the number is a double or triple digit number you write the Number times Position, Number times Position.
It’s actually pretty straightforward when it comes to learning how to use the Japanese number system. Pronouncing Japanese numbers is just as easy to learn.
You really just need to memorizes how to pronounce the base Japanese Numbers then you can easily pronounce any Japanese number. I personally choose to remember that Japanese numbers follow a “number-position” type pattern. Example of what I mean..