Summarize this article in one sentence.
First write out the pH equation. Next, identify the values you have by writing them directly below your equation. For example, if you know the pH is a value of 10.1, write it on the paper below the pH equation. Rearranging the equation will require a strong understanding of algebra. To calculate concentration from pH, you must understand that the inverse of log10 is "10 to the power of ..." Start by shifting the minus sign over from the log side to the pH side. Then raise 10 to the power of (each side). "10 to the power of" and log10 are inverses of each other and cancels out. For example, pH = -log10[H3O+] will mold into [H3O+] = 10-pH.  pH can then be filled in as 10.1 When working with inverse log, the calculator process is unique. Remember that log is a type of multiplication by 10. To enter your equation, key in 10. Next, hit the “EXP” exponent button. Key in the negative sign followed by the value. Hit solve. For example, take a pH value of 10.1. Key in “10” followed by “EXP.” Now key in “-/+” to have our value be negative. Finally, key in the pH of “10.1”. Hit solve. You should get about 7.943ᴇ-11, or 7.943*10-11. This means our concentration is 7.943*10-11 M. A neutral pH of 7 equates to a hydronium ion concentration of 10-7 M. A solution with a pH of 10.1 is basic, so it will have less hydronium ions than that. If we look at our answer, 7.943*10-11, we do indeed see that this number is way smaller than 10-7, so our answer does make sense.

Summary:
Identify the known unknowns. Rearrange the equation. Solve the equation. Think about your answer.