When you or someone you are caring for is seriously ill, it is recommend that you keep EOBs for five years after the illness or condition is alleviated. If you or the patient is claiming or has claimed a medical deduction, keep the explanation of benefits for seven years.
The earliest writing can be traced to Sumer, in Mesopotamia. This system did not use an alphabet, instead it used pictographs which are symbols representing familiar objects. This type of writing was called cuneiform, or wedge-shaped writing. Egyptians used hieroglyphics, also a pictograph system.
At the same time, the Sumerians developed some written notation for mathematics. Writing and mathematics are brain tools--they are powerful aids to the human mind. The abilities to use both written language and mathematics are so useful to people that these are basics in our formal educational system.