6*10^9 does NOT equal 6*10E9

6*10^9 DOES equal 6E9

See the difference? By entering an additional " *10 " to the "E" notation, you have multiplied by an extra 10.

In a calculator, you should be entering "6*10^9" or "6 EXP 9". The 6E9 is a shorthand notation used by engineers and chemists, which may or may not translate well to being used in a calculator, depending on the model of calculator you are using. (I use a Casio, where the "EXP" button is the "E" for that notation.)

I guess I know this stuff because... I'm a chemical engineer and have worked both as an engineer and a chemist.