Conjecturing and generalising

There are 343 NRICH Mathematical resources connected to Conjecturing and generalising
Dotty triangles
problem

Dotty triangles

Age
11 to 14
Challenge level
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Imagine an infinitely large sheet of square dotty paper on which you can draw triangles of any size you wish (providing each vertex is on a dot). What areas is it/is it not possible to draw?
Squares, Squares and More Squares
problem

Squares, Squares and More Squares

Age
11 to 14
Challenge level
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Can you dissect a square into: 4, 7, 10, 13... other squares? 6, 9, 12, 15... other squares? 8, 11, 14... other squares?
Taking Steps
problem

Taking Steps

Age
7 to 11
Challenge level
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In each of the pictures the invitation is for you to: Count what you see. Identify how you think the pattern would continue.
Farey Sequences
problem

Farey Sequences

Age
11 to 14
Challenge level
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There are lots of ideas to explore in these sequences of ordered fractions.
Polite Numbers
problem

Polite Numbers

Age
16 to 18
Challenge level
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A polite number can be written as the sum of two or more consecutive positive integers, for example 8+9+10=27 is a polite number. Can you find some more polite, and impolite, numbers?
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?
Chocolate 2010
problem

Chocolate 2010

Age
14 to 16
Challenge level
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First of all, pick the number of times a week that you would like to eat chocolate. Multiply this number by 2...
How Many Miles To Go?
problem

How Many Miles To Go?

Age
11 to 14
Challenge level
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How many more miles must the car travel before the numbers on the milometer and the trip meter contain the same digits in the same order?
Mind Reading
problem

Mind Reading

Age
11 to 14
Challenge level
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Think of a number, add one, double it, take away 3, add the number you first thought of, add 7, divide by 3 and take away the number you first thought of. You should now be left with 2. How do I know?
Chord
problem

Chord

Age
16 to 18
Challenge level
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Equal touching circles have centres on a line. From a point of this line on a circle, a tangent is drawn to the farthest circle. Find the lengths of chords where the line cuts the other circles.