keurocalc: command not found

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/keurocalc - from package: keurocalc

You may install the required package with command apt-get install {package}

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