Question

Square of 0.0005?

Answer 1

`0.00000025`

Explanation:

To find `0.0005^2` multiply `0.0005xx0.0005`

`0color(red)(.000)5xx0color(red)(.000)5=0color(red)(.000000)25`

In the first expression, you have 6 zeros in total before the 5's, so you would put them as placeholders in the answer, and then
`5xx5=25` so now you have `0color(red)(.000000)25`

Answer 2

If the decimal is giving you a problem use this method:

`0.00000025`

Explanation:

The question is asking for a small part of a small part. So the answer will be less than the original value.

Set `y=(0.0005)^2`

But 0.0005 is the same as `5xx1/(10,000)`

`y=(0.0005)^2 = (5)^2xx(1/(10,000))^2`

`y=25xx1/(100,000,000)`

`y=0.00000025`

As fraction this is `1/4000000`

`color(brown)("However, the question uses decimal notation. So with no")` `color(brown)("instruction otherwise you use the same format as the question.")`

`y=0.00000025`