Question

When the number 0.046508 is reduced to 4 significant figures, then it becomes :

• A. $0.0465$
• B. $4650.8\times$ ${10}^{-5}$
• C. $4.651\times {10}^{-2}$
• D. $4.650\times {10}^{-2}$

Answer 1

The correct option is C $4.651\times {10}^{-2}$

$0.046508\approx 4.6508\times {10}^{-2}$
$\downarrow$
5 significant digits
To have 4 significant digits $\to 4.6508\approx 4.651$
(If the digit to be dropped is more than 5, then the preceding digit is raised by 1)
So, $0.046508\approx 4.651\times {10}^{-2}$