Arithmetic is a form of Elementary school math.

a·rith·me·tic   n. uh-rith-muh-tik; adj. ar-ith-met-ik
noun, slang

a telephone number, generally of a young, attractive female.

The mental process of estimating the respective weights of the other passengers in an elevator. Then comparing it to the maximum weight posted next to the fire inspection sign to see if its safe.

A term describing anything that is very hard to do.
This term has been around for years.

A descriptive term used to describe an extreme erection.

Easy if you know how to spell maths

A dog that walks on three legs and carries one.