This task is about finding a rule for a growing pattern.
Gerry is using matchsticks to make "alien" shapes. He has made three so far.
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| Alien 1 | Alien 2 | Alien 3 |
| a) |
Draw Alien 4 in the space below.
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| b) |
Complete the following table.
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| c) |
Describe, in words, the rule which links the Alien number to the number of matches used.
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| d) |
Using x for the Alien number and y for the number of matches, write your rule as a formula.
y =__________________________________
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| e) |
Show how to use your formula to work out the number of matchsticks needed for Alien 21.
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