Rate x time = Distance.

Today the science class is doing experiments using the RTD formula.  The kids are running or walking down the hall for a specific distance and then figuring out their rate of travel.  This is great because I've been giving my students RTD problems such as "If John travels for 15 min and goes 10 miles, how fast is he going?"  I discovered that my students are not thinking about the units rate normally used.  Most did the 10/15 so the rate is 2/3 or .6667 with no labels. This lead to a discussion of what unit does their answer represent (miles per min).  On Monday, I plan to have them find the rate for a snail, a cougar, a human, a lizard and a couple of other animals.  I plan to write their answers on the smart board or perhaps do a matching on the smartboard and follow this with a discussion about comparing rates with the same units.  This will give them a better perspective and when I compare rates beginning Tuesday, I am hoping they remember to change the rates into the same unit.