Solve with due regard to significant figures.
(i) `46.7 - 10.4 = " "` (ii) `(3.0 xx 10^(-8)) + (4.5 xx 10^(-6)) = `

Explanation

(i) 46.7- 10.04
Here 46.7 has one decimal place, and 10.04 has two decimal places.
`therefore 46.7-10.04= 36.66`
The result should have only one decimal place. The result is 36.7
(ii) `3.0 xx 10^(-8) + 4.5 xx 10^(-6)`
`=0.03 xx 10^(-6) + 4.5 xx 10^(-6)`
`=4.53 xx 10^(-6)`
Here `4.5 xx 10^(-6)` has only one decimal place and `0.03 xx 10^(-6)` can have two decimal places. This result should be rounded off to one decimal place.
`therefore (3.0 xx 10^(-8)) + (4.5 xx 10^(-6))= 4.5 xx 10^(-6)`