Reverse Counting Rule

Reverse Counting Rule


Rule:



  • Start with "0." (decimal point).

  • Count how many times "1" appears in the given numbers.

  • Write the reverse sequence (counting down to 1) after the decimal point.

  • If "1" appears twice, write 21.

  • If "1" appears three times, write 321.


Ex 1: 0.1+0.11=?



  • "1" appears two times.

  • Write reverse counting from 2 to 1 after the decimal.


Ans: 0.21


Ex 2: 0.1+0.11+0.111 = ?


·         "1" appears three times.


·         Write reverse counting from 3 to 1 after the decimal.


Ans: 0.321


Ex 3: 0.4+0.44+0.444+0.4444 = ?


·         This follows a modified rule where a factor (4) is introduced.


·         Factor 4 is multiplied by the result of the Reverse Counting Rule.


4×(0.1+0.11+0.111+0.1111)


·         "1" appears four times, so reverse counting is 0.4321.


·         Multiply by 4:


4×0.4321=1.7284


Ans: 1.7284