Pictograms and block graphs · Usually met around P2
Sorting with Venn and Carroll diagrams
Ask rule by rule: does it fit? Both: the middle.
How to do it
Method
Ask rule by rule: does it fit? Both: the middle
Even, more than 10: 12 in the overlap, 7 outside
Another way
Carroll diagram
Even and more than 10: top left
In full
Sorting diagrams split things by rules. A Venn diagram has two rings, a rule each: things fitting only the left rule go in the left ring, only the right rule in the right ring, both rules where the rings overlap, and neither outside the rings. So ask of each thing, rule by rule: does it fit? A Carroll diagram draws the same sorting as four cells: the columns are one rule, yes or no; the rows the other, yes or no; fitting both goes top left. When counting what is inside a ring, remember the overlap is inside it too.
Worked examples
Have a go first, then open each one for the answer and the working.
Example 1
How many numbers in the Venn diagram are outside both rings?
Show the answer and working
Answer: 1
The numbers outside fit neither rule: count them, 1.
Example 2
How many numbers are inside the left ring of the Venn diagram, the overlap included?
Show the answer and working
Answer: 4
The left ring holds 2 in it alone and 2 in the overlap: 2 + 2 = 4.
Example 3
2 belongs where the two rings overlap.
True or false?
Show the answer and working
Answer: True
The overlap needs both rules to fit: check 2 against each.
Practise it in the game →Pictograms and block graphs · Free to start, unlimited questions, no download