Exploring and noticing

There are 412 NRICH Mathematical resources connected to Exploring and noticing
Out of Sync
problem

Out of sync

Age
11 to 14
Challenge level
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Albert Einstein could see two clocks which were out of sync. For what fraction of the day did they show the same time?
Sticks and Triangles
problem

Sticks and triangles

Age
7 to 11
Challenge level
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Using different numbers of sticks, how many different triangles are you able to make? Can you make any rules about the numbers of sticks that make the most triangles?
Impossible triangles?
problem

Impossible triangles?

Age
16 to 18
Challenge level
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Which of these triangular jigsaws are impossible to finish?
It's a Fence!
problem

It's a fence!

Age
5 to 11
Challenge level
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In this challenge, you will work in a group to investigate circular fences enclosing trees that are planted in square or triangular arrangements.
Newspaper Sheets
problem

Newspaper sheets

Age
14 to 16
Challenge level
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From only the page numbers on one sheet of newspaper, can you work out how many sheets there are altogether?
Stairs
problem

Stairs

Age
5 to 11
Challenge level
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This challenge is to design different step arrangements, which must go along a distance of 6 on the steps and must end up at 6 high.
Calendar Capers
problem

Calendar capers

Age
11 to 14
Challenge level
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Choose any three by three square of dates on a calendar page...
Difference
problem

Difference

Age
7 to 11
Challenge level
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Place the numbers 1 to 10 in the circles so that each number is the difference between the two numbers just below it.
Top-Heavy Pyramids
problem

Top-heavy pyramids

Age
11 to 14
Challenge level
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Use the numbers in the box below to make the base of a top-heavy pyramid whose top number is 200.
Amazing Alphabet Maze
problem

Amazing alphabet maze

Age
5 to 7
Challenge level
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Can you go from A to Z right through the alphabet in the hexagonal maze?