      * https://rosettacode.org/wiki/Binary_digits#COBOL
        IDENTIFICATION DIVISION.
        PROGRAM-ID. SAMPLE.

        DATA DIVISION.
        WORKING-STORAGE SECTION.

        01 binary_number   pic X(21).
        01 str             pic X(21).
        01 binary_digit    pic X.
        01 digit           pic 9.
        01 n               pic 9(7).
        01 nstr            pic X(7).

        PROCEDURE DIVISION.
        accept nstr
        move nstr to n
        perform until n equal 0
          divide n by 2 giving n remainder digit
          move digit to binary_digit
          string binary_digit DELIMITED BY SIZE
          binary_number DELIMITED BY SPACE
          into str
          move str to binary_number
        end-perform.
        display binary_number
        stop run.
