How do I install php-gd on CentOS 7?

I need to install php-gd on CentOS 7. I have very limited repositories on my network. I cannot get a direct connection to the Internet with a Linux server. I tried to install php56w-gd-5.6.19.1.w7.x86_64.rpm But it needs php56w-common-5.6.19.1.w6.x86_64.rpm which depends on libgmp.so.3 I get the error that this .so.3 file is required. I cannot find this so.3 file on the Linux server. So the error message is correct. gmp.x86_64 is installed. Yum list gmp shows it. I tried installing these packages:gmp-4.3.1-7.el6_2.2.i686.rpm and gmp-4.3.1-7.el6_2.2.x86_64.rpm. I tried a different way of installing php-gd. I used rh-php56-php-gd-5.6.5-7.el7.x86_64. But I got a message about it not updating the installed package. I tried yum clean all. But when I repeated my installation attempts of the .rpm packages, I got the same problems. I then tried two more gmp packages: gmp-4.1.4-10.el5.x86_64.rpm and gmp.4.1.4-12.3_2.el5.x86_64.rpm Neither would install. From gmplib.org I downloaded a .tar.gz file to install gmp 6.1 It installed fine. But it failed to produce a libgmp.so.3 file. yum list gmp shows that gmp 6.0 is installed. What package will satisfy my need for a libgmp.so.3 requirement? Is there a different way to install php56w-common-5.6.19-1.w6.x86_64.rpm or php56w-gd-5.6.19.1.w7.x86_64.rpm? I need to get php-gd installed with version 5.6 (not any lower). Update: rh-php56-php-gmp.x86_64 was successfully installed.