Vortex Math: Summing the Digits of a Number is just the Remainder

In this video I show that the "vortex sum" of a number (summing up the digits until obtaining a single digit is obtained) is just the remainder when dividing the number by 9. I go over a couple of examples while also illustrating why this is the case by writing the transition numbers 10, 100 as (9 + 1), (99 + 1). YouTube - Summary - Notes - Playlist

#math #vortexmath #modulararithmetic #algebra #education

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