What numerically unique features accompany the number 9?

Answer 1

Some numerically unique features of the number 9are:(note symbol [~] for metathesis or "putting together") In Addition: # 1 + 9= 10~1+0=1 # 2 + 9= 11~1+1=2 # 3 + 9= 12~1+2=3 # 4 + 9= 13~1+3=4 # 5 + 9= 14~1+4=5 # 6 + 9= 15~1+5=6 # 7 + 9= 16~1+6=7 # 8 + 9= 17~1+7=8 # 9 + 9= 18~1+8=9 The metathesis of whatever is added to 9 will always equal the metathesis of the sum. eg. 21 x 32=672~6, 672 + 9=681~6 This is also true of multiples of 9. eg. 2 + 27= 29~11~2 In Multiplication: # 01 x 9= 09~9 # 02 x 9= 18~9 # 03 x 9= 27~9 # 04 x 9= 36~9 # 05 x 9= 45~9 # 06 x 9= 54~9 # 07 x 9= 63~9 # 08 x 9= 72~9 # 09 x 9= 81~9 # 10 x 9= 90~9 Whatever 9 multiplies will result in a sum whose metathesis is 9. eg. 88 x 9 = 792~18~9 This is also true of multiples of 9. eg. 6 x 63= 378~18~9 In Subtraction: The same unique features accompany 9 if the sum is not a negative number. eg.[1~]10 - 9= 1, [2~]11- 9= 2, [3~]12 - 9= 3, etc. In Division: Except for whole multiples of 9, whenever a number is divided by 9, its metathesis repeats to an infinite number of decimal places. # 01 / 9= 0.111111r # 02 / 9= 0.222222r # 03 / 9= 0.333333r # 04 / 9= 0.444444r # 05 / 9= 0.555555r # 06 / 9= 0.666666r # 07 / 9= 0.777777r # 08 / 9= 0.888888r # 09 / 9= 1. # 10 / 9= 1.111111r # 11 / 9= 1.222222r # 12 / 9= 1.333333r # 13 / 9= 1.444444r # 14 / 9= 1.555555r # 15 / 9= 1.666666r # 16 / 9= 1.777777r # 17 / 9= 1.888888r # 18 / 9= 2.