Use the the term 3 Musketeer method

MODE = MOST ofter seen
MEDIAN = MIDDLE - list least to greatest, min. to max. etc. leap frog from both ends to the middle - unless list is too great
Mean = line them up - add them up - divide them up
Range = hangs around for the ride - Home on the Range seaches for lost animals in the low places and the high places - then subtract

I have had reasonalbe success - using this on 4th graders - working with 5th for the first time this year