PRINT "3.141592653589793 = ", Dec2Frac$ (3.141592653589793)


FUNCTION Dec2Frac$ (Argument AS SINGLE)
  DIM RAW a     AS SINGLE
  DIM RAW b     AS SINGLE
  DIM RAW c     AS INTEGER
  DIM RAW d     AS INTEGER
  DIM RAW e     AS INTEGER
  DIM RAW f     AS INTEGER
  DIM RAW num   AS SINGLE
  DIM RAW den   AS SINGLE
  DIM RAW ratio AS SINGLE
  DIM RAW mult  AS INTEGER

  IF Argument < 0.0 THEN
    FUNCTION = "Argument cannot be negative"
  END IF

  a = Argument
  b = 1.0
  c = 1
  d = 0
  e = 0
  f = 1

  DO
    mult = a / b
    a -= mult * b
    c -= mult * d
    e -= mult * f
    num =- e
    den = c
    ratio = num / den

    IF Argument - ratio < 0.00000001 THEN
      EXIT LOOP
    END IF

    mult = b / a
    b -= mult *a
    d -= mult *c
    f -= mult *e
    num = f
    den = - d
    ratio = num / den

    IF ratio - Argument < 0.00000001 THEN
      EXIT LOOP
    END IF
  LOOP

  FUNCTION = REMOVE$(STR$(f) + "/" + STR$(-d)," ")
END FUNCTION