BECE Mathematics 2013 Paper

Express $4956 \times 25 = 123,900$ in the form of $495.6 \times 2.5$$4956 = 4956.0$ (Every whole number has .0 )$25 = 25.0$ (Every whole number has .0 )$4956 = 495.6 \times 10^1$Note: The decimal point is moved to the left once, hence the power is 1$25 = 2.5 \times 10^1$$495.6 \times 10^1 \times 2.5 \times 10^1 = 123,900$$495.6 \times 2.5 \times 10^1 \times 10^1 = 123,900$$a^1 = a, 10^1 = 10$$495.6 \times 2.5 \times 10 \times 10 = 123,900$$10 \times 10 = 100$$495.6 \times 2.5 \times 100 = 123,900$ Divide both sides by 100 so that you obtain $495.6 \times 2.5$ as requested by the question.$495.6 \times 2.5 = \frac{123900}{100}$Note: The zeros (0) in 123900 and 100 cancel each other.$495.6 \times 2.5 = 1239$$495.6 \times 2.5 = 1.239 \times 10^3$ in standard formNote:1239 = 1239.0For standard form, the decimal point must be after the first non-zero digit. We must therefore move the decimal point three times to the left and multiply by $10^{\text{number of moves (3)}}$.