Input Validation muliples of 100?

[Sabensohn70]

I am suppose to write a code to validate that the users input is between 0-4000 and are multiples of 100. How do i write a code to ensure that the cin is multiples of 100? So far i have

cin >> store1;
if ( store1 < 0 || store1 > 4000 )
{
     cout << " Invalid entry ";

I just dont know how to make it so the program knows whether the cin is multiples of 100 or not.