My Strange Observation: Anything Multiplied by 9 Equals 9

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SUMMARY

The discussion centers on the mathematical observation that any number multiplied by 9 results in a sum of digits that equals 9. This phenomenon is attributed to the properties of the number 9 in base 10 arithmetic. Additionally, similar properties are noted for the numbers 1 in binary and 2 in ternary systems, indicating a broader mathematical principle regarding the largest integer in various numeral systems.

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decibel
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i was playing with numbers the other day and noticed this

- Anything multiplied by 9, will equal 9 when added

this is really weird considering that it doesent work with any #

i know this belongs in the math forums, but using physics could generate a good theory,

it may be stupid but u never know...so any thoughts?, any observations would be appreciated also
 
Last edited:
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You will find the same "strangness" attached to 1 in a binary system, 2 in a teriary system. This behavior is a property of the largest integer.

Yes this belongs in the Math forums.
 

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