Screening candidates Over Phone - templates and checklist that might be helpful?

I am an experienced HR professional with 5 years of experience in ER. I quit job 4.5 years back as marriage and baby. Now I am planning to start again and got some work with freelancing option. As I was in Employee relations can you please share some templates and checklist that might be helpful during process. I got some work and have to screen over phone. Now, this job need people with good reasoning and numeric ability..can you suggest how I can assess same. Additional info is appreciated.

Think about how will you find out if someone has good reasoning and numeric ability?
Right, by answering questions which test these skills.
Now, where do you get such questions?
Google, quiz books, aptitude test books!
Look up some 5-7 places, make a list of questions preferably sort them by difficulty level and then, voila, you are ready!