Flashcard 1 - Upper Level: Quantitative Reasoning Flashcard Set for the ISEE

\[4.56 \;x \;10^{-9}\]

Move the decimal \(9\) places to the right so that the resulting number is greater than \(1\), but less than \(10\) (\(4.56\), in this case).
The exponent a is \(-9\) because we moved the decimal \(9\) spaces to the right.

Scientific notation is written in the standard form:

\[N\; x \;10^a\]

where N is a number greater than 1 but less than 10; and a is a positive or negative integer determined by the number of spaces the decimal point was moved to get N.

Moving the decimal to the left results in a positive exponent; moving it to the right results in a negative exponent.