JAMB Mathematics 2021 Paper

Concept:Evaluate the expression first, then round the decimal value to $4$ significant figures.Explanation:Square the bracket first:$$(3 \times 10^{-3})^{2} = 3^{2} \times (10^{-3})^{2} = 9 \times 10^{-6}.$$Then multiply by $241.34$:$$241.34 \times 9 \times 10^{-6} = 2172.06 \times 10^{-6} = 0.00217206.$$Now round $0.00217206$ to $4$ significant figures.The first significant digit is $2$, so the first four significant digits are $2$, $1$, $7$, $2$.The next digit is $0$, which is less than $5$, so the digit stays the same.Thus, the value to $4$ significant figures is $0.002172$.Answer:$0.002172$