if statement with multiple values

Hello everyone, i am happy to be a new member here.

I am trying to write a statement that recognizes (a) , every 1000 increments,

How do i do that,

ofcourse there is a++

this is how i have it now,
if ((a == 1000) && (value_read>= 3.5)){
myloop();

if ((a == 2000) && (value_read>= 4.5))
myloop();

if ((a == 3000) && (value_read>= 4.5))
myloop();

if ((a == 4000) && (value_read>= 4.5))
myloop();

if ((a == 5000) && (value_read>= 4.5))
myloop();

if ((a == 6000) && (value_read>= 4.5))
myloop();

if ((a == 7000) && (value_read>= 4.5))
myloop();

}
thank you

and apologies for not reading the forum rules before hand, i tried to edit my post but it gave me 30 seconds to do so, i was late.

Is it a new thing newbies can't edit? ???

But anyway (assuming 4,5 for the other value everywhere):

 if ((a % 1000  == 0) && (value_read>= 4.5)){
    myloop();
}

Note you have to constrain a somewhere (depending on the type) to not run into overflow.

Thank you, that works great.