If $0.01$ is $10$ to the negative 2nd power then what is $0.2$?
I am having trouble making all the test tubes a number that can be added together.
Test tube A is $.01 = 10$ to the negative 2nd power
Test tube B is $.1 = 10$ to the negative 1st power
Test tube C is $.2= $?
You need to use logarithms. $$\log_{10}(0.2)=-\log_{10}(5) \approx -0.69897$$
so $$0.2 \approx 10^{-0.69897}.$$