BECE Mathematics 2015 Paper

Concept:Standard form expresses a number as $a \times 10^{n}$, where $1 \leq a < 10$ and $n$ is an integer. This requires placing the decimal point after the first non-zero digit.Explanation:The given number is $625.13$.The first non-zero digit is $6$, so the decimal point must be placed immediately after $6$, giving $6.2513$.Count how many places the decimal point moves from its original position to the new position. It moves two places to the left.When the decimal is moved to the left, the exponent $n$ is positive. Therefore, $n = 2$.Write the new decimal multiplied by $10^{n}$:$625.13 = 6.2513 \times 10^{2}$.This matches Option C.Answer:$6.2513 \times 10^{2}$Correct option: C.