SUBJECTS: Maths
YEARS: 5–6, 7–8
Did you know that 6,174 is a very mysterious number?
In 1949, the mathematician Dr Kaprekar from India devised a process now known as Kaprekar's operation.
First, choose a four-digit number where the digits are all different.
Then rearrange the digits to get the largest and smallest numbers these digits can make.
Finally, subtract the smallest number from the largest to get a new number, and carry on repeating the operation for each new number.
You always reach 6,174: a constant.
Acknowledgements
Video © GAPC Entertainment.
Date of broadcast: 12 Nov 2018
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