When going form standard form to scientific notation, we need to move the decimal point. If the decimal point is moved to the right, the exponent is negative. If we move the decimal point to the left, the exponent is positive.
0.0005421
Move the decimal point so that there is one non-zero digit to the left of the decimal point.
In this case we would move the decimal point to the right of the 5.
By doing so, we are moving the decimal point, 4 digits to the right, so the exponent is -4
0.0005421 = 5.421 x 10-4
6.9
Since scientific notation require one non-zero digit to the left of the decimal, there are no changes necessary here.
There is no need to move the decimal point.
6.9 = 6.9 x 100
568,400
Remember, even though we don't see the decimal point, it is in fact to the right of the 2nd 0.
Move the decimal point that that there is one non-zero digit to the left of the decimal point.
In this case we would move the decimal point to the right of the 5
By doing so, we are moving the decimal point 5 digits to the left, so the exponent is 5
568400 = 5.684 x 105
