The paper presents a way of calculation in the method of the diagnosis and recommendation integrated system DRIS, described in Appendix 5 by Reuben B. Beverly, in the book of J. Benton Jones Jr, Benjamin Wolf and Harry A. Mills. 1991. Plant Analysis Handbook – a practical sampling, preparation, analysis, and interpretation guide. Micro - Macro Publishing, Inc., Athens, Georgia, USA. In the appendix R.B. Beverly described a simple method to calculate and interpret DRIS index values. Dr R.B. Beverly noted that, “In practice, DRIS indices are generally calculated using computers. For the sake of understanding and practicing DRIS calculations, sample problems have been designed so that calculations can be made with a hand calculator.”