Bike pedometer

[~Wingnut~]

Hi!
We have started going on family bike rides and I have my sister's old bike with a pedometer (is that what it is called?) attached but she can't remember what the little symbols mean. Please could someone help me work out what they are thanx :o)
First one is O
then D, I know this one is distance.
Then A, which has us stumped.
Then T, which we know is time whilst cycling.
Then M, but it reads 22.7 not long after cycling so it's not miles which we intitially thought.
then it has S which I know is speed.

So it's just really the O, A & M which we don't know.
Much appreciate any help thanx! (there's no name on the pedometer so can't look it up)

[~Wingnut~]

Thank you for your help. Sorry but didn't know what else to call it.