10 Logarithms on your calculator
Logarithms to base 10 of numbers can be found using the 
key. For example, 
can be calculated using the key sequence 
. Note that as with the trigonometric functions, the key automatically opens a bracket that must be closed if you are using the calculated logarithm as part of a longer calculation.
The second function of the key 
, accessed using 
, can be used as an alternative to 
when calculating powers of 10.
Activity 19 Calculating logarithms
Use your calculator to find the values of the following.
, 
, 
(1 billion) , 
Answer
All the calculations are logarithms to base 10, so we use the key.
, 
, (1 billion) 
, 
.