Numbers

How to read figures.
1 ; ichi
2; ni
3; san
4; yon
5; go
6; roku
7; nana
8; hachi
9; kyuu
10; juu(not mention "ichi")
100; hyaku(not mention "ichi")
1,000; sen(not mention "ichi")
10,000 ; ichi-man
100,000,000; ichi-oku

Almost of figures can be read by using the combination of pronunciation listed above.

20; ni+juu=nijuu
22; ni+juu+ni=nijuuni
1,035; sen +san+juu+go=sen sanjuu go
16,256; ichi+man+roku+sen+ni+hyaku+go+juu+roku=ichiman rokusen nihyaku gojuu roku

en ; yen
harau ; pay

Watashi-wa hyaku-en o harau; I , 100yen , pay →I pay 100yen.
Watashi-wa hyaku-en o haraimasu.(more polite); I pay 100 yen.

ikura; how much

Kore-wa ikura desuka?; this, how much, is→ How much is this?
Hyaku-en desu.; 100yen, is→This is 100yen.