Fibonacci sequence

There are 31 NRICH Mathematical resources connected to Fibonacci sequence
Fibonacci Surprises
problem
Favourite

Fibonacci surprises

Age
11 to 14
Challenge level
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Play around with the Fibonacci sequence and discover some surprising results!

Fibs
problem
Favourite

Fibs

Age
11 to 14
Challenge level
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The well known Fibonacci sequence is 1 ,1, 2, 3, 5, 8, 13, 21.... How many Fibonacci sequences can you find containing the number 196 as one of the terms?
1 Step 2 Step
problem
Favourite

1 step 2 step

Age
11 to 14
Challenge level
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Liam's house has a staircase with 12 steps. He can go down the steps one at a time or two at time. In how many different ways can Liam go down the 12 steps?
LOGO Challenge - Circles as bugs
problem

Logo challenge - circles as bugs

Age
11 to 16
Challenge level
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Here are some circle bugs to try to replicate with some elegant programming, plus some sequences generated elegantly in LOGO.
Fibonacci Deduction
problem

Fibonacci deduction

Age
11 to 14
Challenge level
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Leonard writes down a sequence of numbers. Can you find a formula to predict the seventh number in his sequence?
Stringing it Out
problem

Stringing it out

Age
14 to 16
Challenge level
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Explore the transformations and comment on what you find.
Last Biscuit
game

Last biscuit

Can you find a strategy that ensures you get to take the last biscuit in this game?

Ordered Sums
problem

Ordered sums

Age
14 to 16
Challenge level
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Let a(n) be the number of ways of expressing the integer n as an ordered sum of 1's and 2's. Let b(n) be the number of ways of expressing n as an ordered sum of integers greater than 1. (i) Calculate a(n) and b(n) for n<8. What do you notice about these sequences? (ii) Find a relation between a(p) and b(q). (iii) Prove your conjectures.
Fibonacci Factors
problem

Fibonacci factors

Age
16 to 18
Challenge level
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For which values of n is the Fibonacci number fn even? Which Fibonnaci numbers are divisible by 3?