These are marked log and ln. The log key is used for calculations of the form \({\log _{10}}x\). For example, to work out that \(\log 10000 = 4\) you would press \(\log 10000 =\) Using this method ...

Taken from Introduction to Econometrics from Stock and Watson, 2003, p. 215: Y=B0 + B1*ln(X) + u ~ A 1% change in X is associated with a change in Y of 0.01*B1 ln(Y)=B0 + B1*X + u ~ A change in X by ...