Number bases

There are 24 NRICH Mathematical resources connected to Number bases
Oh for the mathematics of yesteryear
problem

Oh for the mathematics of yesteryear

Age
11 to 14
Challenge level
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A garrison of 600 men has just enough bread ... but, with the news that the enemy was planning an attack... How many ounces of bread a day must each man in the garrison be allowed, to hold out 45 days against the siege of the enemy?
Back to Basics
problem

Back to Basics

Age
14 to 16
Challenge level
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Find b where 3723(base 10) = 123(base b).
Basically
problem

Basically

Age
11 to 14
Challenge level
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The number 3723(in base 10) is written as 123 in another base. What is that base?
Happy Octopus
problem

Happy Octopus

Age
11 to 14
Challenge level
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This investigation is about happy numbers in the World of the Octopus where all numbers are written in base 8 ... Find all the fixed points and cycles for the happy number sequences in base 8.
Base Puzzle
problem

Base Puzzle

Age
11 to 14
Challenge level
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This investigation is about happy numbers in the World of the Octopus where all numbers are written in base 8 .Octi the octopus counts.
Basic Rhythms
problem

Basic Rhythms

Age
16 to 18
Challenge level
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Explore a number pattern which has the same symmetries in different bases.
Binary Squares
problem

Binary Squares

Age
16 to 18
Challenge level
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If a number N is expressed in binary by using only 'ones,' what can you say about its square (in binary)?
Nim
problem

Nim

Age
14 to 16
Challenge level
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Start with any number of counters in any number of piles. 2 players take it in turns to remove any number of counters from a single pile. The loser is the player who takes the last counter.
Code to Zero
problem

Code to Zero

Age
16 to 18
Challenge level
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Find all 3 digit numbers such that by adding the first digit, the square of the second and the cube of the third you get the original number, for example 1 + 3^2 + 5^3 = 135.
It must be 2000
problem

It must be 2000

Age
7 to 11
Challenge level
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Here are many ideas for you to investigate - all linked with the number 2000.