Code: PU P=100 (k=80=0 (mod 20) )
Formulae:
Number N is divisible by 20 iff least significant digit is divisible by 20
Example:
Number N = 98 76 54 32 20
is divisible by 20.
Code: PS, CR
P=2*10, (k=2)
Formulae:
Number N is divisible by 20 iff least significant digit with base 20 is 0
Example:
Number N = 68940 with base P=10
[6, 8, 9, 4 | 0] = [6, 8, 8, 14 | 0] = 2*[3, 4, 8, 7] 0
Number N is divisible by 20. Other digits:
[3, 4, 4 | 7] = [2, 14, 4 | 7] = 2*[1, 7, 2] 7
[1, 7 | 2] = [0, 16 | 12] = 2*[0, 8] 12
[0 | 8] = 2*[0] 8
So N = 8 12 7 0 with base 20
