BECE Mathematics 2015 Paper

For standard form, the decimal point must be after the first non-zero digit In 625.13 , the first non-zero digit is 6 , hence we must move the decimal point to the front of 6Step 1Count while moving the decimal point.6. 2 $5.13=6.2513$ with two movesStep 2Multiply the new decimal by $10^{n}$Where $n$ is the number of times you have to move the decimal pointIf you move the decimal point to the left, $n$ is positive but if you move to the right $n$ is negative.In 625.13 , we have to move the decimal point two times to the left, hence $n=2$Standard form of $625.13=6.2513 \times 10^{2}$