more than one formula for 1) calculator shell
    

        # TCL source code follows
        # pretty print from autoindent and ased editor
        # Biological Mutation Rate calculator V2
        # written on Windows XP on TCL
        # working under TCL version 8.6
        # gold on TCL Club, 12Dec2018
        package require Tk
        package require math::numtheory
        namespace path {::tcl::mathop ::tcl::mathfunc math::numtheory }
        set tcl_precision 17
        frame .frame -relief flat -bg aquamarine4
        pack .frame -side top -fill y -anchor center
        set names {{} {mutation rate years (1/N) :} }
        lappend names {number of females:}
        lappend names {offspring per female: }
        lappend names {geologic interval years : }
        lappend names {mutation years:}
        lappend names {mutation years: }
        lappend names {mutation years: }
        lappend names {mutations per geologic interval: }
        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 about {} {
            set msg "Calculator for Biological Mutation Rate
            from TCL
            # gold on TCL Club, 12Dec2018 "
            tk_messageBox -title "About" -message $msg }
        proc self_help {} {
            set msg " Biological Mutation Rate V2
            from TCL ,
            # self help listing
            # problem, Biological Mutation Rate V2
            # 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, th
            # 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
            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
            global testcase_number
            incr testcase_number
            set side1 [* $side1 1. ]
            set side2 [* $side2 1. ]
            set side3 [* $side3 1. ]
            set side4 [* $side4 1. ]
            set side5 [* $side5 1. ]
            set side6 [* $side6 1. ]
            set side7 [* $side7 1. ]
            set side8 [* $side8 1. ]
            set generation_interval_years $side1
            set females $side2
            set offspring $side3
            set geologic_interval $side4
            set offspring_over_interval [* $females $offspring ]
            set mutation_instance [ expr { (1.0 * $generation_interval_years)/( $females * $offspring )  } ]
            set mutation_instance2 [ expr { (1.0 * $geologic_interval)/ $mutation_instance } ]
            set side6 $mutation_instance
            set side7 $mutation_instance
            set side8 $mutation_instance2
        }
        proc fillup {aa bb cc dd ee ff gg hh} {
            .frame.entry1 insert 0 "$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 answer2
            global side1 side2 side3 side4 side5
            global side6 side7 side8
            global testcase_number
            global wavelength wavelength2
            global wavelength6 wavelength10
            global wavelengthsq surfacearea
            global megafrequency
            console eval {.console config -bg palegreen}
            console eval {.console config -font {fixed 20 bold}}
            console eval {wm geometry . 40x20}
            console eval {wm title . " Biological Mutation Rate Report V2, screen grab and paste from console 2 to texteditor"}
            console eval {. configure -background orange -highlightcolor brown -relief raised -border 30}
            console show;
            puts "%|table $testcase_number |printed in| tcl format|% "
            puts "&| quantity| value| comment, if any|& "
            puts "&| $testcase_number :|testcase_number | |&"
            puts "&| $side1 :|mutation rate years (1/N):  |   |&"
            puts "&| $side2 :|number of females:   | |& "
            puts "&| $side3 :|offspring per female: | |& "
            puts "&| $side4 :|geologic interval years:  | |&"
            puts "&| $side5 :|mutation years: | |&"
            puts "&| $side6 :|mutation years: |  |&"
            puts "&| $side7 :|mutation years: |  |&"
            puts "&| $side8 :|mutations per geologic interval: |  |&"
        }
        frame .buttons -bg aquamarine4
        ::ttk::button .calculator -text "Solve" -command { set side8 0 ; calculate   }
        ::ttk::button .test2 -text "Testcase1" -command {clearx;fillup 25E6 5000. 5. 1.7E6 1000. 1000. 1000. 1700. }
        ::ttk::button .test3 -text "Testcase2" -command {clearx;fillup 20E6 7000. 5. 0.6E6 1000. 570. 570. 1050. }
        ::ttk::button .test4 -text "Testcase3" -command {clearx;fillup 10E6 9000. 5. 0.8E6 1000. 222. 222. 3600. }
        ::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 . "Biological Mutation Rate Calculator V2"