Venn Diagrams
Crazy Animals Software
The maths education site Maths300 has a free sample lesson about Crazy Animals. The lesson has free software which will load onto Windows and Mac computers, but not iPads or some other devices. Go to the Maths300 Sample Lessons link and scroll until you find the software download.
 Play thousands of Crazy Animal games in a few seconds.
The teachers' lesson notes, which are linked at the top of the sample lesson page, will guide you in using the software further.

A Venn diagram can be used to see show how the sets of data in a problem are connected.
This is a Venn diagram for Crazy Animals.
The name is spelt with a capital V because they were invented by John Venn around 1880.
Answer these questions in your journal.
 Copy the sketch into journal so it takes at least half a page.
Don't copy the animals that are already written there.
 The animals that are written are made from just the horse and the giraffe.
How does the diagram show that?
 Put your horse and giraffe beside each other.
Show yourself how the Haffe has been made then write it in.
 Repeat for all the other names in this part of the diagram.
 Are there any other 3 part animals made from just the horse and the giraffe?
How do you know?
 How many 3 part animals can be made using the horse and the duck?
Put their names on your diagram.
 How many 3 part animals can be made using the giraffe and the duck?
Put their names on your diagram.
 Explain what the section in the middle of the diagram means.
Predict how many animals should be in this section, then write in their names.
 There should be twentyseven (27) animal names on the diagram.
Have you got them all?
Equations
To work out the number of animals in the middle you could think about the number of choices.
 The animals in the middle must have one piece from each animal.
 Head first  3 choices
 Body second  2 choices (because one animal has been used for the head)
 Legs third  1 choice because the other animals have already given their part.
 So, for each of the 3 head choices there 2 body choices and then the rest is automatic.
 That's two body choices for that head, another two for that head and another two for that head. Then only one other choice  the automatic one.
 The equation that summarises this is 3 x 2 x 1 = 6.
 Create and explain an equation that calculates the total number of crazy animals if 3 animals are split into 3 parts?
 What is the total if 3 animals are split into only 2 parts?
 What happens if 2 animals are split into 3 parts?
 What happens if 4 animals are split into 3 parts?
 The next mathematician's question might be:
If I tell you any number of animals and any number of parts, can you tell me how to work out the total number of crazy animals?
