gcalccmd: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/gcalccmd - from package: gnome-calculator

You may install the required package with command apt-get install {package}
Error in other languages:
gcalccmd: bevel nie gevind nie
gcalccmd: comandă negăsită
gcalccmd: comando não encontrado
gcalccmd: commande introuvable
gcalccmd: command not found
gcalccmd: käsku ei ole
gcalccmd: không tìm thấy lệnh
gcalccmd: komanda nerasta
gcalccmd: Kommando nicht gefunden.
gcalccmd: kommandot finns inte
gcalccmd: komut yok
gcalccmd: nie znaleziono polecenia
gcalccmd: níor aimsíodh an t-ordú
gcalccmd: no se encontró la orden
gcalccmd: no s'ha trobat l'ordre
gcalccmd: opdracht niet gevonden
gcalccmd: parancs nem található
gcalccmd: perintah tidak ditemukan
gcalccmd: príkaz nenájdený
gcalccmd: příkaz nenalezen
gcalccmd: команда не найдена
gcalccmd: командата не е открита
gcalccmd: 命令找不到
gcalccmd: コマンドが見つかりません