Number patterns

Question 2

Here is a pattern of shapes made from matches.

4 diagrams
Detailed description of diagram

a Write down a sequence of 6 numbers giving the number of matches in each of these diagrams and the next two in the obvious sequence.
b Give the rule for finding the next term in this pattern.

Solution

How do you go from diagram 1 to diagram 2?
You add 3 matches in the manner shown.
How do you go from diagram 2 to diagram 3?
You add 3 matches.
This can be continued to produce each successive diagram.

a Term 1: 4   Term 2: 7   Term 3: 10
  Term 4: 13   Term 5: 16   Term 6: 19
b Add 3