My manager is doing our timecards wrong and shorting employees pay- what should I do?

I used to do the timecards and she said I was doing them wrong. Here is the deal: We alway rounded hours to the quarter (.25 , .50 , .75). So if someone is working from 8:30 to 11:58 it would be 3.50 hours. But she is doing it all on a calculator so when she puts 11:58 minus 8:30 it says 3.28 so she is putting 3.25 on the timecard.
I tried to explain to her that the calculator is in 100ths and the timeclock is in minutes but she just yanked the timecards out of my hand and told me I was not to do them anymore. I don't know what to do - the other employees have not noticed. Should I just contact the department of labor or try something else?

It is not affecting me because I work 8 hour shifts and she is the main boss so there is no one to report her too. I work at a hotel and it is the housekeepers that are being cheated out of hours.

In the the grownup world of work and business, I have found one rule I have always followed to be invaluable.

The rule? "Pick your battles." Look at each situation that you find uncomfortable or that miffs you and ask yourself, "How will it effect my career? Win and/or lose" and "Is it worth risking my good standing with the boss?"

Is it worth going to war over a few pennies? You can try to explain it to one of the people it effects and then back away but even this is risky because you already said something to the boss about it, They will guess that you contacted the worker. Risk/reward, measure it.

Can you photocopy or take a picture of your timecard before you turn it in? Is there a corporate HR office you can contact? It's illegal for them to not pay you for the hours you've worked. Be prepared to prove you're being shorted.

If you can prove what you say, confront your boss about it. That way if he fires you then you can sue him.

From what you say, I suspect that your manager is NOT trying to cheat you....I suspect that she is just plain "Stupid"...obviously she doesn't understand the concept of 60 minutes as opposed to percentages. it's fairly obvious that she does not take criticism very well either. I would suggest that you discreetly speak with her boss, and see what can be done, without getting yourself in the dog house. Going to the department of labour, or suing for lost wages, will result in short term gain, but long term pain. You will earn a reputation as a troublemaker. This reputation will follow you in the future, when it comes time for possible promotion or even prospective new employer.

So...if someone actually works their full shift to 12, they get overpaid? Management isn't going to like that either.