Express in scientific notation:
0.00045 −2.5 times 10 to the negative 5th power

4.5 × 10 − 3

Step-by-step explanation:

Note that moving decimal  

p

digits to right is equivalent to multiplying by  

10

p

and moving decimal  

q

digits to left is equivalent to dividing by  

10

q

.

Hence, we should either divide the number by  

10

p

i.e. multiply by  

10

−

p

(if moving decimal to right) or multiply the number by  

10

q

(if moving decimal to left).

In other words, it is written as  

a

×

10

n

, where  

1

≤

a

<

10

and  

n

is an integer.

To write  

0

,

0045

in scientific notation, we will have to move the decimal point three point to right, which literally means multiplying by  

1000

=

10

3

.

Hence in scientific notation  

0.0045

=

4.5

×

10

−

3

(note that as we have moved decimal three point to right we are multiplying by  

10

−

3

.

1010: 3030

is it i think