numbers.....?
 

Ok so here's the deal. When I first started learning to speak Japanese with my friend, I learned the numbers like so:

1 - ichi
2 - ni
3 - san
4 - shi
5 - go
6 - roku
7 - shichi
8 - hachi
9 - kyu
10 - ju

Of course that's only the first 10 numbers bu anyway, I was just reading a book about Japanese language that my mom bought me and two of the numbers are different. The number 4 in the book is 'yon', rather than 'shi' and the number 7 in the book is 'nana' rather than 'shichi'.

Can anyone explain this to me please? I would like to know what the correct one is before I start learning a bunch of Japanese. Thank you.

yon and shi are both correct for 4
and nana and shichi are both correct for 7
but people prefer to use yon and nana
because in japanese shi is associated with death :O

Basically, they use yon and nana because the sounds are more destinct than shi and shichi