How to install BC Math and configure PHP to use BC Math?

[root@myvps ~]# yum install php-bcmath
Loaded plugins: fastestmirror, security
Setting up Install Process
Determining fastest mirrors
epel/metalink                                            | 3.3 kB     00:00
 * epel: fedora.mirror.serversaustralia.com.au
base                                                     | 3.7 kB     00:00
base/primary_db                                          | 4.7 MB     00:03 ...
epel                                                     | 3.2 kB     00:00
epel/primary                                             | 3.2 MB     00:00
epel                                                                                                                   12516/12516
extras                                                                                                      | 3.4 kB     00:00
extras/primary_db                                                                                           |  26 kB     00:00 ...
mysql-connectors-community                                                                                  | 2.5 kB     00:00
mysql-connectors-community/primary_db                                                                       |  26 kB     00:00
mysql-tools-community                                                                                       | 2.5 kB     00:00
mysql-tools-community/primary_db                                                                            |  45 kB     00:00
mysql57-community                                                                                           | 2.5 kB     00:00
mysql57-community/primary_db                                                                                | 152 kB     00:00
updates                                                                                                     | 3.4 kB     00:00
updates/primary_db                                                                                          | 1.8 MB     00:00 ...
Resolving Dependencies
--> Running transaction check
---> Package php-bcmath.x86_64 0:5.3.3-49.el6 will be installed
--> Processing Dependency: php-common(x86-64) = 5.3.3-49.el6 for package: php-bcmath-5.3.3-49.el6.x86_64
--> Running transaction check
---> Package php-common.x86_64 0:5.3.3-49.el6 will be installed
--> Finished Dependency Resolution

Dependencies Resolved

===================================================================================================================================
 Package                          Arch                         Version                            Repository                  Size
===================================================================================================================================
Installing:
 php-bcmath                       x86_64                       5.3.3-49.el6                       base                        40 k
Installing for dependencies:
 php-common                       x86_64                       5.3.3-49.el6                       base                       530 k

Transaction Summary
===================================================================================================================================
Install       2 Package(s)

Total download size: 569 k
Installed size: 3.0 M
Is this ok [y/N]: y
Downloading Packages:
(1/2): php-bcmath-5.3.3-49.el6.x86_64.rpm                                                                   |  40 kB     00:00
(2/2): php-common-5.3.3-49.el6.x86_64.rpm                                                                   | 530 kB     00:01 ...
-----------------------------------------------------------------------------------------------------------------------------------
Total                                                                                              286 kB/s | 569 kB     00:01
Running rpm_check_debug
Running Transaction Test
Transaction Test Succeeded
Running Transaction
Warning: RPMDB altered outside of yum.
  Installing : php-common-5.3.3-49.el6.x86_64                                                                                  1/2
  Installing : php-bcmath-5.3.3-49.el6.x86_64                                                                                  2/2
  Verifying  : php-bcmath-5.3.3-49.el6.x86_64                                                                                  1/2
  Verifying  : php-common-5.3.3-49.el6.x86_64                                                                                  2/2

Installed:
  php-bcmath.x86_64 0:5.3.3-49.el6

Dependency Installed:
  php-common.x86_64 0:5.3.3-49.el6

Complete!