I plug an iPod into a computer and display the images on a wall or interactive screen. If you put up a collection of songs, ask pupils to arrange them in order of time. Clarify whether you mean ascending or descending.
I get pupils to find the range of the times (the biggest number minus the smallest), then I invite them to find the middle number in the list (median) and the number which occurs most often (mode).
I ask the pupils how long it would take to play all the songs, then to find the mean and decide which number: mean, mode or median best represents the data.
Another starter is to ask them to say what time the music will stop if we start playing it at, say, 0915. If we want the songs to finish at noon, what time should we start playing them?
Suppose we have a target number in mind, for example 15 minutes of break time. What collection of songs, when added together, would get us closest to that target number?
For another set of starters, suppose the iPod can hold 7,500 songs. The mean average song is, say, 2 minutes, 40 seconds long. How long would it take to play all the songs? Would the battery need recharging?
If 7,500 songs were on CDs and each CD was in a standard case, how tall would it be? If we laid the CDs on the floor, what area would we cover?
I ask pupils to get into teams and do as many calculations as they can think of in a set time. I also ask them to say why these would be useful and to whom.
Gatsby teacher fellow, Gosford Hill School, Kidlington