Scientific Notation is a short-hand way of writing or displaying very large or very small numbers. This method is often used when precise accuracy is not needed or not practical (as when comparing milimeters to light years). 1,234,567,890 in scientific notation would be written as 12.35 x 108 12.35 is 12.34567890 rounded to the nearest 100th. A positive exponent (e.g. +8), or 108, tells us to move the decimal 8 places to the RIGHT. So if we were to re-write the number in long-hand without knowing the original value, it would become 1,235,000,000 (not exact, but close enough for comparison) 0.001000034 in scientific notation would be written as... 1.00 x 10-3 A negative exponent (e.g. -3), or 10-3, tells us to move the decimal 3 places to the LEFT.  If we were to re-write this number in long-hand, it would become 0.001 (again not exact, but close enough) NOW all you need to know is, when viewing very large or very small results from these calculators, the computer can't easily display 12.35 x 108 or 1.00 x 10-3, so it will display the numbers like this... 12.35 x 108 would be written as 12.35E+8 and 1.00 x 10-3 would be written as 1.00E-3 In other words, scientific notation on a computer will use E-3 or E+8 to represent 10-3 and 108 respectively (I have always wanted to use respectively in a sentence). These examples were kept simple, but normally the computer will return many more digits after the decimal (e.g. 12.3558384939E+15), but that should not be a problem if you understand these examples.