index - a numerical scale used to compare variables with one another or with some reference number. 1  margin of error, margin of safety, safety margin - the margin required in order to insure safety; in engineering the margin of safety is the strength of the material minus the anticipated stress.
Nutty Ways to Celebrate Squirrel Appreciation Day This Year. SQUIRRELS! Whether you love them or loathe them, National Squirrel Appreciation Day, January 21st, is a great time to take a few moments and learn about these nutty animals. If you count flying squirrels we have 10 tree species in North America.
National Teacher Appreciation Day: Chick-fil-A, Chipotle, Amazon Prime and other freebies. Chick-fil-A is offering a free chicken sandwich to all teachers on Tuesday, May 3 for National Teacher Appreciation Day. Today is May 3, but in schools around the country, many are taking the time to acknowledge a teacher. It's National Teacher Appreciation Day. So, teachers put down those lesson plans and head out to celebrate at one of the many businesses offering you a discount or even a free meal. Teachers and staff who show school ID on May 3 at select Chick-fil-A locations will get a free chicken sandwich.