The EXP or EE button on a calculator means 'multiply by 10 to the power of'

If you need to enter a negative power you have to press the + button to get the negative sign - don't use the arithmetic 'minus sign'

To enter 1.65 x 10^-7 into your calculator you have to press the following buttons:

1 . 6 5 EXP + 7

You do NOT need to press the 'x' button at all!... and you don't need to put in the '10'