If I’m applying to, say 10 schools, do my recommenders have to write the recommendations 10 different times or 1 for all colleges will be just fine? Plus, can I scan and e-mail the recommendations to the respective colleges?
Recommenders write only one time in the common app. You assign based on each school’s allowed numbers.
Schools allow a certain number of recs. If you believe additional recs are absolutely warranted to provide significantly different perspective about you, you may be able to send directly to the admissions office - via portal or email or even fax in some cases.
Also, schools usually expect you to waive your right to review recs. So, you should not be emailing or faxing. Recommenders should do it directly.