How do I increased speed everytime a certain variable reached?

Hey I need a help to make increased speed of bullet everytime this certain of variable is reached. The logic is probably like this : every multiple of 2000 variable (ex : 2000,4000,6000), the bullet speed increased by 50 (it's start with 100 and when I reach 2000 the bullet's speed would be increased to 150. And when I reach 4000 the bullet's speed would be increased to 200 ). I'm sorry for my bad english. I hope someone would understand it and help me with it.

Set bullet speed to 100+int(variable/2000)*50

Set bullet speed to 100+int(variable/2000)*50

thank you, It works. If I can bother you more, can you explain it to me? How the script worked know when to added speed for every 2000 ? (0 skill at programming)

int() expression means integer, it removes everything after decimal point.

For example:

int(3.14)=3

int(5210/2000)=2

thank you for the answer