Here is a set of numbers... What do you think they represent? These are actually a set of temperatures recorded in London last year.

What is different about the set now?

....and now?

This data becomes a stem-and-leaf diagram when we introduce a stem and write the rest of the data as ‘leaves’. Key: 1| 3 = 13 o

We can use these diagrams to find averages and range Mode... Most Common Mode = 3 = 13 

We can use these diagrams to find averages and range Median... Middle Number Median = 13 There are 30 numbers so the middle value is half way between the 15 th and 16 th value

We can use these diagrams to find averages and range The range is easy The largest and smallest value are there for all to see... Range = = 34

Right HandLeft Hand Key:

Reaction, s, secondsFrequencyMid PointMid Point x Freq