stdio.h not found

We've got a new Linux box here and looks like somethings not quite right. Trying to compile a simple c program:

[~/c/h2]% gcc heat.c
heat.c:1:19: stdio.h: No such file or directory
heat.c:2:18: math.h: No such file or directory


***? What didn't get installed? Or am I missing a path?

I finally figured it out. The *-devel-* packages were missing. Too many had been installed and they were _all_ removed to clean up space on /usr. I installed a half dozen or so back and now everything works.