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.
Home Calendar Holidays Fun Crush a Can Day. Take out all your frustrations and anger and be green and environmentally friendly at the same time by crushing a can to celebrate Crush A Can Day on September 27. Aluminum cans crushed For recycling in a Child's hands.Crushing cans is a both a satisfying and an eco-friendly activity.Â©bigstockphoto.com/obkatrina.