So i need some help with scientific notation?

Question

here are the problems 004200 15100.00 00.0025 1.00094 19100.00

Answer 1

Scientific notation or sig figs?

if there's no decimal in the first one its 4.2X10^3

2) 2.5X10^-3

3) its already in scientific notation

4) 1.91X10^4

For scientific notation you take the number and put it into the singles place and then multiply it by a certain number of tens to get it to the correct place.

Answer 2

4.2 x 10^3

1.510000 x 10^4

2.5 x 10^-3

1.00094

1.910000 x 10^4

Pay attention to significant figures.  For instance, zeros to the right of the decimal point indicate precision.  The way I was taught, I use a "bar" over the last significant zero to the immediate left of the decimal point.  None of these numbers had that.  (I'm wondering if that is what the leading zeros are for.)

Answer 3

4.2 x 10^3

1.51 x 10^4

2.5 x 10^(-3)

1.00094 x 10^0

1.91 x 10^4