(i) 360000 written in standard form is 3.6 × 105
360000 = 36 × 104 = 3.6 × 10 × 104 = 3.6 × 10(1+4) = 3.6 × 105
(ii) 0.0000123 written in standard form is 1.23 × 10-5
0.0000123 = \(\frac{123}{10000000}=\frac{123}{10^7}\)
\(=\frac{1.23\,\times\,100}{10^7}=\frac{1.23\,\times\,10^2}{10^7}\)
= 1.23 × 10(2-7) = 1.23 × 10-5
(iii) \((\frac{-2}{3})^{-2}=\frac{9}{4}\)
\((\frac{-2}{3})^{-2}=(\frac{3}{-2})^2=\frac{3^2}{-2^2}=\frac{9}{4}\)
(iv) 3 × 10-3 in usual form is 0.003
3 × 10-3 = \(\frac{3}{10^3}=\frac{3}{1000}=0.003\)
(v) 5.32 × 10-4 in usual form is 0.000532
5.32 × 10-4 \(=\frac{5.32}{10^4}=\frac{5.32}{10000}=0.000532\)