Need Advice: Masters or PhD

I would really appreciate any advice or suggestions anyone might have. I am currently a senior mathematics major, about to graduate in May. For two years, I have planned on going for my PhD in pure mathematics (my highest interests have been in algebra, number theory, and discrete math). I applied to 8 PhD programs and 1 masters program, the masters program just for the heck of it. I was accepted into the masters program, but I was rejected from 6 PhD programs and wait-listed on the other two. Neither of these last two would I really want to go to, but I would be happy at either of them nonetheless.

Now, the masters program is at Ohio State and gives full tuition waiver plus a minimum monthly stipend of $1950, plus a significantly reduced health insurance bill. The program specifically is the Master of Mathematical Sciences with concentration in Computational Sciences. The department is super lenient as to which courses I can take outside of their main core courses, as long as my course plan fits the computational theme and as long as my advisor signs off.

So, my question is, should I go to the masters program or should I go to one of the PhD programs (if I'm even accepted; again, I'm still wait-listed)? Will finishing this MMS program at Ohio State help my chances of getting in to a top-notch PhD program in the future? How common is it (in mathematics) for mathematicians to earn a (non-"incidental") masters degree before pursuing their PhD?

Thanks! Let me know if you want any clarification or further information.