pseudocode can be developed from rules of thumb.
    pseudocode: enter diameter in cm, number of atoms in oil molecule
    pseudocode: output film thickness in nanometers
    pseudocode: average of atoms equals film thickness/ (number_of_atoms)
    pseudocode: rules of thumb can be 3 to 15 percent off, partly since g..in g..out.
    pseudocode: need test cases > small,medium, giant
    pseudocode: need testcases within range of expected operation.
    pseudocode: are there any cases too small or large to be solved? 

        # pretty print from autoindent and ased editor
        # Oil Molecule Calculator
        # written on Windows XP on eTCL
        # working under TCL version 8.5.6 and eTCL 1.0.1
        # gold on TCL Club , 2may2014
        # comment follows from gold, 12Dec2018
        # pretty print from autoindent and ased editor
        # Oil Molecule Calculator V2
        # written on Windows XP on TCL
        # working under TCL version 8.6
        # Revamping older program from 2014.
        package require Tk
        namespace path {::tcl::mathop ::tcl::mathfunc}
        frame .frame -relief flat -bg aquamarine4
        pack .frame -side top -fill y -anchor center
        set names {{} { initial drop volume, cubic  millimeters:} }
        lappend names { diameter oil slick (average dimension) centimeters::}
        lappend names { number of atoms in molecule: }
        lappend names { answers:  oil molecule nanometers:}
        lappend names { oil atom (average) nanometers:}
        lappend names { oil atom (average) nanometers:}
        lappend names { oil atom (average) nanometers:}
        lappend names { oil atom (average) nanometers:}
        foreach i {1 2 3 4 5 6 7 8} {
            label .frame.label$i -text [lindex $names $i] -anchor e
            entry .frame.entry$i -width 35 -textvariable side$i
            grid .frame.label$i .frame.entry$i -sticky ew -pady 2 -padx 1 }
        proc pi {} {expr acos(-1)}
        proc about {} {
            set msg "Calculator for Oil Molecule V2
            from TCL ,
            # gold on  TCL Club, 12Dec2018  "
            tk_messageBox -title "About" -message $msg }
        proc self_help {} {
            set msg " Oil Molecule Calculator V2
            from TCL Club ,
            # self help listing
            # problem, Oil Molecule Calculator V2
            # 3 givens follow.
            1) initial drop volume, cubic  millimeters:
            2) diameter oil slick (average dimension) centimeters:
            3) number of atoms in molecule:
            # Formulas in calculator makes
            # assumptions on how oil molecules and atoms
            # are stacked and oriented in
            # an oil slick.
            # 1) Assumption: oil atoms are
            # stacked vertically, due to
            # electostatic forces on the oil molecule.
            # 2) Assumption: the oil
            # slick is one molecule thick.
            # 3) Assumption: The oil atom has the thickness
            # of the oil molecule divided by the
            # given number of atoms.
            # Recommended procedure is push testcase
            # and fill frame,
            # change first three entries etc, push solve,
            # and then push report.
            # Report allows copy and paste
            # from console to conventional texteditor.
            # For testcases, testcase number is internal
            # to the calculator and will not be printed
            # until the report button is pushed
            # for the current result numbers.
            # >>> copyright notice <<<
            # This posting, screenshots, and TCL source code is
            # copyrighted under the TCL/TK license terms.
            # Editorial rights and disclaimers
            # retained under the TCL/TK license terms
            # and will be defended as necessary in court.
            Conventional text editor formulas
            or  formulas grabbed from internet
            screens can be pasted into green console.
            # gold on  TCL Club, 12Dec2018 "
            tk_messageBox -title "Self_Help" -message $msg }
        proc calculate { } {
            global answer2
            global side1 side2 side3 side4 side5
            global side6 side7 side8 testcase_number
            incr testcase_number
            set dropvol $side1
            set diameter_oil_slick  $side2
            set numberatoms $side3
            set height [ expr {  (4.*$side1*1E6)/([pi]*$side2*$side2)} ]
            set side4 $height
            set side5 [ expr { ($side4/$side3)} ]
            set side6 [ expr { ($side4/$side3)} ]
            set side7 [ expr { ($side4/$side3)} ]
            set side8 [ expr { ($side4/$side3)} ]
            return $side5
        }
        proc fillup {aa bb cc dd ee ff gg hh} {
            .frame.entry1 insert 0 "$aa"
            .frame.entry2 insert 0 "$bb"
            .frame.entry3 insert 0 "$cc"
            .frame.entry4 insert 0 "$dd"
            .frame.entry5 insert 0 "$ee"
            .frame.entry6 insert 0 "$ff"
            .frame.entry7 insert 0 "$gg"
            .frame.entry8 insert 0 "$hh" }
        proc clearx {} {
            foreach i {1 2 3 4 5 6 7 8} {
                .frame.entry$i delete 0 end } }
        proc reportx {} {
            global side1 side2 side3 side4 side5
            global side6 side7 side8 testcase_number
            global nonopttotal mergedx
            console eval {.console config -bg palegreen}
            console eval {.console config -font {fixed 20 bold}}
            console eval {wm geometry . 40x20}
            console eval {wm title . " Oil Molecule Calculator V2 Report, screen grab and paste from console 2 to texteditor"}
            console eval {. configure -background orange -highlightcolor brown -relief raised -border 30}
            console show;
            puts "%| table |printed in| tcl format|% "
            puts "&| quantity| value| comment, if any|& "
            puts "&| testcase number| $testcase_number||& "
            puts "&| initial drop volume millimeters:| $side1 ||&"
            puts "&| diameter oil slick centimeters:| $side2||& "
            puts "&| number of atoms in molecule :| $side3||& "
            puts "&| answers:  oil molecule height :| $side4 ||&"
            puts "&| oil atom (average) nanometers:| $side5||& "
            puts "&| oil atom (average) nanometers:| $side6 ||&"
            puts "&| oil atom (average) nanometers :| $side7 ||&"
            puts "&| oil atom (average) nanometers :| $side8 ||&"
        }
        frame .buttons -bg aquamarine4
        ::ttk::button .calculator -text "Solve" -command { calculate   }
        ::ttk::button .test2 -text "Testcase1" -command {clearx;fillup .005 60. 12.0  1.76  .15 .15  .15 .15}
        ::ttk::button .test3 -text "Testcase2" -command {clearx;fillup .065 220. 12.0  2.0 .15 .15 .15 .15}
        ::ttk::button .test4 -text "Testcase3" -command {clearx;fillup .125 280. 12.0 2. .15 .15  .15  .15}
        ::ttk::button .clearallx -text clear -command {clearx }
        ::ttk::button .about -text about -command about
        ::ttk::button .self_help -text self_help -command { self_help }
        ::ttk::button .cons -text report -command { reportx }
        ::ttk::button .exit -text exit -command {exit}
        pack .calculator  -in .buttons -side top -padx 10 -pady 5
        pack  .clearallx .cons .self_help .about .exit .test4 .test3 .test2   -side bottom -in .buttons
        grid .frame .buttons -sticky ns -pady {0 10}
        . configure -background aquamarine4 -highlightcolor brown -relief raised -border 30
        wm title . "Oil Molecule Calculator V2"
             

  puts " %| testcase $testcase_number | value| units |comment |%"
  puts " &| volume| $volume| cubic meters |based on length $side1 and width $side2   |&"