counting money and telling time

When counting yen and telling time, there are 2 numbers that are used differently.
These two number are 4 and 7.

For counting money:
7 - nana en (7 yen)
4 - yon en (4 yen)
Also when counting money, soushite (and) is used.
For example:
yonsen-en soushite sen-en gosen-en desu (4,000 yen and 1,000 yen is 5,000 yen)

*Also, to say the phrase "isn't it", ja arimasen ka is used.
For example:
senzen-en ja arimasen ka? - Isn't it 3,000 yen?


For telling time:
7 - shichi ji (7 o'clock)
4 - yo ji (4 o'clock)

Some phrases when telling time is as follows:
hachiji ni - at 8 o'clock
hachi ji desu - it's 8 o'clock
hachi ji wa? - how about 8 o'clock?