Answers
 

 

Explanation

This section is very straightforward once you understand logarithms and scales, and once you do, you do not need a calculator to answer the questions. For example:
Q 84     10^3.7 = 5012 (answer 2)
Using our understanding of log₁₀ scales, without the calculator, 10³ = 1,000 and 10⁴ = 10,000.
Thus 10^3.7 must be in between the two. As the scale is not linear, but logarithmic, there is a much smaller difference between 10³ and 10^3.1 (1000 to 1250) than there is between 10^3.8 and 10^3.9 (6310 to 7940). That is how logarithmic scales work. For 10^3.7 = ~ 7000, the scale between the decimal points would have to be linear, and we know that it isn't. Thus 10^3.7 = ~5000.
If you have trouble with following this through go back to your calculators and learn how to use the 10^x button, although that does defeat some of the purpose of this section as it is important that you grasp the non-linear nature of logarithmic scales.