double type problem

 
what happens is that is that nesesito make a program that takes an integer for example 1.345678 and remove the value of 78 or another example 2.346798 and remove the 98.

Can not use string commands converters to run this program double to integer.

I did was that totals the number goes 2.0 1.63960 kept them in another tank then subtracts the second with the first 2.00000 - 1.63960 = 0.36040
then subtract 1.00000 - 0.36040 and 0.63960 should I could use the figure to% but this command is for integers.
 

1) 1.123123 is a double an not an interger

NormalizeDouble(1.345678,4) does return 1.345600

Reason: