Question

Express each of the following numbers in the standard form :
a) $0.00000000000942$
b) $0.0035\times {10}^{-6}$
c) $0.002\times 0.006$

Answer 1

Standard form: $A\times {10}^b$

where $1\le A<10$

(1)

$0.00000000000942=9.42\times {10}^{-12}$

It is ${10}^{-12}$ because the decimal point has been moved $12$ places to the right to get the number to be $9.42$

(2)

$0.0035\times {10}^{-6}=3.5\times {10}^{-3}\times {10}^{-6}$

$=3.5\times {10}^{-9}$

(3)

$0.002\times 0.006=2.0\times {10}^{-3}\times 6.0\times {10}^{-3}$

$=12\times {10}^{-6}$

$=1.2\times 10\times {10}^{-6}$

$=1.2\times {10}^{-5}$