Answer
See the explanation
Work Step by Step
i.
Significant numbers constitute the definite digits that are unmistakable in a measurement and possible digits that are indeterminate.
ii.
In $1000$, there is only one significant number. Similarly, in $1$. there is only one significant figure.
In $1.0 \times 10^1$, there are two significant numbers. Similarly, this number $(10.)$ has two significant figures.
In $1.00 \times10^2$, there are three significant numbers. Similarly, this number $(100.)$ has three significant figures.
In $1.000 \times 10^3$, there are four significant numbers. Similarly, this number $(1000.)$ has four significant figures.
iii.
In this equation, the accurate answer is $1$.
$$\frac{1.5-1.0}{0.50}=\frac{0.5}{0.50}=1.$$
The answer $1.0$ is erroneous because the zero counts as a significant number. The answer for the equation should be one significant number because the limiting term $(0.5)$ has a single significant number.
