Look in the RTL viewer (or Technology map viewer) in Quartus, you will see implantation of your design.
Quartus synthetize your "adder" with Logic Elements. So many Logic Elements will be used.
Quartus synthetize your "mult" with inside DSP and a (very) few Logic Elements. You should see that in ressources report.
For information for newbies, DSP is Digital Signal Processing that is especially optimized to multiply and add.
About your "divider":
Dividing is complex to synthetize, except those /2, /4, /8, /16 ...
Be aware of timing requirements, you may need to use "pipeline" generic