What should I do?

Okay, so earlier this week I was drafting a post in my head about how this year, I have mellowed out about certain things. For example, many sixth graders aren't so great at long division involving decimals. In the past, I might have insisted that they divide using decimals or I might have tried to teach them how, or both, and it would probably have ended in a protracted bout of frustration for all of us. This year, when I'm modeling how to solve speed = distance/time problems, I do the problem using a remainder and then using a decimal, and tell them to use whichever they feel most comfortable with, but to start trying to use decimals because that's the more grown-up way to divide. I will let them climb on-board the decimal wagon whenever they are ready or their math teachers get them ready. Everyone is happier.

Except that we gathered data on how long it takes us to speedwalk down the hallway, and I asked them to compute their speeds in m/s, and tonight they have to find the class average, and how the heck do you find an average when you have a whole bunch of numbers with remainders?!

A couple of kids asked me over the course of the day, and I told them I'd think about it and let them know how to handle it tomorrow. What am I going to tell them?

I could work out the mathematics, but what I am really looking for is something simple to tell them to solve the problem for this lab report, not some complicated method to teach them. I don't want to get bogged down; I just want to find a way for them to get accurate averages, finish their lab reports. and move on.

Please help!