Mammoth Memory

Indices and decimal places 

What is 100.2 ?

The way to tackle these problems is (if you can) turn the decimal into a fraction.

So  100.2=10210  

And we now know this equals

10210=(1010)2 

Which reads

Work out what we have to multiply by itself 10 times to get 10, then multiply the answer by itself 2 times.

In this case:

1010=1.259  (see logarithms)

And  (1.259)2=1.259×1.259 

=1.585  

                    

Answer:

100.2=1.585