# 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) , .

OpenLearn - Using a scientific calculator
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