You cannot do what you are trying to do. There is no direct correspondence between some number of bits and a decimal digit.
With hexadecimal, every 4 bits corresponds to exactly 1 hex digit. That is why hex is used for computers.
One hex digit represents exactly 4 bits. Every time you add another hex digit, you add 4 bits.
Two hex digits corresponds to exactly a byte. 00h to FFh represents a value from 0 to 255.
There is no such direct correspondence between binary and decimal. If you have 4 bits, it takes 1 or 2 decimal digits to represent it (0-15) If you have 8 bits, it takes 1, 2, or 3 decimal digits to represent it, but there are 3 digit decimal values (values > 255) that you can't represent with 8 bits.
Binary Hex Decimal
0000 0 0
0001 1 1
0010 2 2
0011 3 3
0100 4 4
0101 5 5
0110 6 6
0111 7 7
1000 8 8
1001 9 9
1010 A 10
1011 B 11
1100 C 12
1101 D 13
1110 E 14
1111 F 15
You simply cannot convert a binary number to decimal using bit shifting and masking.
As @Kwasmich says in their answer, the closest you're likely to come would be to convert your binary value to BCD (Binary coded decimal) where each 4 bits holds a decimal digit. You could convert THAT to decimal character output using masking and shifting.
