How to install bcmath in Ubuntu for PHP 7.1
Answering my own question. Managed to fix this issue with following repo update.
add-apt-repository ppa:ondrej/phpapt updateapt install php7.1-bcmath
Restart apache and all good to go.
install this : https://packages.ubuntu.com/fr/artful/amd64/php7.1-bcmath/download
add this :
deb http://security.ubuntu.com/ubuntu artful-security main universe
to /etc/apt/sources.list
$ sudo apt update$ sudo apt install php7.1-bcmath
Those who are looking for Ubuntu 20.04:
sudo apt install php-bcmath
It will automatically install the bcmath compatible with your version of PHP.