funcalc: 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
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

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/funcalc - from package: funtools

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