This is a good free maths worksheet to encourage systematic ordering of data. Lists of highest mountains, longest rivers and largest turtles are given, but they are not in order. There is a definite technique in efficiently putting these in order as it is very easy to miss one and not so easy to rearrange them if you are doing it on paper!
For example, take the mountains. They are all over 8000 m in height, so the key number to look at is the hundreds digit. Find the highest (Everest) and mark a 1 next to it. Find the second highest and mark it with a 2 and so on. Then rewrite them according to the marks.
Some good spin-off work here for Geography – can they find the mountains, rivers etc?