How to convert dec num2 binary in libre writer

i created a table in libre writer , i tried to convert decimal numbersin one coloums to binary in other colum , but it showing faulty expression

i used dec2bin(A4) ;;; Here A4 Previous row

DEC2BIN() requires 2 arguments, the second argument is the number of bits.
For a binary string of length=8 you could write DEC2BIN(A4;8)