Some Math Shortcuts

Some Math Shortcuts

– shared by bunny

1. MULTIPLICATION TABLES SHORTCUT

BASE 2 TO 9 TABLES

A. 11 to 19 tables
12 means table of 2 , 13 means 3 , 14 means 4 , 15 means 5 and so on..

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B. 21 to 29 tables

Same 22 means 2 , 23 means 3 , 24 means 4 and so on… but

For eg.

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C. 31 to 39 tables

Same 32 means 2 , 33 means 3 and so on

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D. 41 to 49 tables

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2. DIGITAL ROOT / NUMEROLOGY

the sum of digits of a number is known as digital root (DR). These lies between 1 to 9.

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3 while subtraction if :

(a) DR of number 1 > DR of number 2
Ex. 215 – 40 = 175 ( 1+7+5 =13=1+3=4)
8 – 4 = 4 ( 2+1+5=8,4+0=4)

(b) DR of number 1 = DR of number 2
Ex. 50-5 =45 (4+5=9)
( 5-5 = 9)

100-1=99 (9+9=18,1+8=9)
( 1-1 =9)

20 – 2 = 18 (1+8=9)
(2-2 = 9)

Your ans. 9 always

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Digital root is very helpful in simplification/ approximation . but this method is not apply on every question.

There is ALWAYS A POSSIBILITY / OPTION for something better , if you are willing to accept what you have is not your ONLY OPTION ……

Regards
Bunny

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