Use the form below to do your conversion.
Solution
Step1
Log21689=Log(689) ÷ Log(21)
Log(689)= 2.8382192219076
Log(21)=1.3222192947339
Log21689=2.8382192219076 ÷ 1.3222192947339
Ans=2.146557105324
Step2
Alternatively, the logarithm can be calculated like this.