600 → roppyaku
This is because saying "roku hyaku" would just be too much. Therefore, they shortened it to "roppyaku". Here, you have the "p" sound because when saying "ro-," your mouth shape transitions to the "p" sound more easily than it would transition to the "b" sound.
300 → sanbyaku
This is because "san hyaku" would make your mouth move too much; it's tiring. Therefore, they changed it to "sanbyaku" because when you make the "n" sound in "san," your mouth shape transitions easier to the "b" sound instead of an "h" sound.
Does this help you? I hope you can understand what I am trying to say. Good luck!
March 22, 2015 at 6:25am