Clickety Click and All the Sixes
Age 16 to 18
Challenge Level
Why do this
problem?
A non-standard problem based on place value and summing geometric
series requiring simple manipulation of a numerical
expression.
Possible approach
A short problem suitable as a lesson starter.
Key questions
Can you write the 10 digit number $6666666666$ as a geometric
series?
Can you sum this series?
Can you do the same for any number that is a 'string of
sixes'?
Possible extension
For a discussion of a generalisation of this problem see
Sum The Series.