You may wish to take a look at Measuring with Rods before trying this problem.
Charlie has been exploring the lengths he can measure with two different rods:
Alison has been exploring the lengths she can measure if she adds a third rod:
Is there only one set of three rods that will allow Alison to measure the largest number of consecutive lengths?
What if she could use a set of four rods?... Or five? ...
Is there a way to determine the ideal lengths for any number of rods?
Is there a quick way to work out how far a set of rods will allow you to measure?
What would happen if you could only add lengths together, and couldn't subtract?