Going on Sensation next week and read the "automatic" gratuities are $10/day per person. Is it standard and common to tip the same amount per child? We're traveling with our 8 & 9 yr-olds.

Yes it is commom for the tips to be the same for the kids, you will find that the staff usually goes out of their way to entertain the kids and make sure they have a great time.

The gratuities are also automatically added to your S&S account for the children.

If they are planning on eating, sleeping in a bed and  taking showers using towels and useing any of the facilities for children, then I guess it is a common practice.  They wash the childrens dishes the same as yours and they get clean towels every day.  They will serve them dinner the same as you.  They will probably be even nicer to the children than they will be to you.  If thats possible.  You will see that they earn every penny making this a wonderful vacation for you and your family.  Have a great cruise!

About as standard and custom as when you go to a restaurant, and tip the waiter/waitress for their service.

 Is'nt it normal for a dinner out to tip 15% to 20% of your total bill. I know if we go out at a nice restaurant the bill will come to at least $80 to !00 dollars. tip should be 15 to 25 for good service.and thats just one meal.  Iwould think 10 bucks a day is a very reasonable cost for the anticipated services. provided.  I'm really looking forward to our first cruise. 

Yes, this is standard.  The staff makes the cruise and are great with children!

Happy Sailing