The approximate value of the number \( 1.3\cdot10^{-0.4} \) is \( 0.5175393 \). What is the approximate value of the number \( 39\cdot10^{0.6} \)? Give your answer to three decimal places. Do not use a calculator.
The approximate value of the number \( 10^{0.1} \) to five decimal places is \( 1.25893 \). Give the approximate value of the number \( 10^{-0.9} \) to three decimal places. Do not use a calculator.
Numbers \( \left(2^2\right)^{\left(2^2\right)} \), \( \left(2\right)^{\left({2^2}^2\right)} \), \( \left({2^2}^2\right)^2 \), \( \left(2\right)^{\left(2^2\right)^2} \) were written on the board. How many different numbers are represented by these records?