Jimo Fortune-telling Formula _ Where is Feng Shui in Jimo?

What about the decimal point of fortune-telling formula?

=round(( 100- year of birth) /9, 1)- Round to integer 4.6 to get the result 5; 4.4 Obtaining Results 4

=ceiling(( 100- year of birth) /9, 1)- round up 4. 1 to get the result of 5; 4.8 also leads to 5.

=int(( 100- year of birth) /9)- round down 4.9 to get the result 4; 4. The result of1is 4.