Question

Taking into account of the significant figures, what is the value of $9.99\text{m}-0.0099\text{m}$ ?

• A. $9.980\text{m}$
• B. $9.9\text{m}$
• C. $9.9801\text{m}$
• D. $9.98\text{m}$

Answer 1

The correct option is D $9.98\text{m}$

Here $9.99\text{m}-0.0099\text{m}=9.9801\text{m}$

However according to rule, "the number of significant figures in the final answer should be equal to the minimum number of significant figures present in any of the given numbers".
The least number of significant figure present is $2$.

$\therefore 9.99\text{m}-0.0099\text{m}=9.98\text{m}$.