Question

Try these without a calculator. On these, dont round. Do convert final answers to scientific notation. Do the odds first, then the evens if you need more practice.

1. (61 x 10⁻⁷) + (2.25 x 10⁻⁵) + (212.0 x 10⁻⁶) =2. ( ― 54 x 10⁻²⁰ ) + ( ― 2.18 x 10⁻¹⁸ ) =3. ( ― 21.46 x 10⁻¹⁷ ) ― ( ― 3,250 x 10⁻¹⁹ ) =

Answer 1

1)
`2.406e^(-4)`

2)
`-5.618e^(-19)`

3)
`-2.14275e^(-16)`

Explanation:

1) First you need to reorder the terms, to do a simple sum:

(61 x 10⁻⁷) + (2.25 x 10⁻⁵) + (212.0 x 10⁻⁶) =

`6.1e^(-6) + 22.5e^(-6) + 212e^(-6)=`

Now you can simply sum each term, because the exponential is the same:

`240.6e^(-6)=\\ 2.406e^(-4)`

2) First you need to reorder the terms, to do a simple sum:

( ― 54 x 10⁻²⁰ ) + ( ― 2.18 x 10⁻¹⁸ ) =

`-5.4e^(-19) - 0.218e^(-19)=`

Now you can simply sum each term, because the exponential is the same:

`-5.618e^(-19)`

3) First you need to reorder the terms, to do a simple sum:

( ― 21.46 x 10⁻¹⁷ ) ― ( ― 3,250 x 10⁻¹⁹ ) =

`-21.46e^(-17) + 0.0325e^(-17)=`

Now you can simply sum each term, because the exponential is the same:

`-21.4275e^(-17)=\\-2.14275e^(-16)`