Question

How do you evaluate `(4\times 10^ { - 6} ) + ( 0.08\times 10^ { - 2} )`?

Answer 1

We first change the second number `=8xx10^(-4)`

Explanation:

Since this is the largest of the two, also change the first number, so it has the same `10`-power: `=0.04xx10^(-4)`

And now we can add: `=(8+0.04)xx10^(-4)=8.04xx10^(-4)`

Note:
There is a significance issue here. Since both numbers are given with a 1-digit significance, the smaller number does not make a significant difference, and the answer should be `=8xx10^(-4)`

Answer 2

`0.000804` or `8.04 xx10^-4`

Explanation:

`(4 xx 10^-6)+(0.08 xx 10^-2)`

`(4 xx 1/10^6)+(0.08 xx 1/10^2)`

`4/1000000+0.08/100`

`0.000004+0.0008`

`:.=0.000804` or `8.04 xx 10^-4` `rarr(8.04/10000)`