We think it's best for all children to start at the very beginning of Story Mode, on Rust Level 1, and work their way through the stages consecutively. This is for a number of reasons:
All children benefit from reaffirming the foundations of maths.
You can be sure they have not missed out on any key maths skills which could trip them up later when the levels get more complex.
Children become accustomed to the way different types of levels work and familiar with the various representations.
They'll notice patterns and similarities between easier questions and more difficult ones, which will help them to answer the difficult ones.
They'll become more invested in the story of Rusty if they start at the beginning.
They'll receive rewards and unlock certain features at the optimum time to be most motivational.
Nevertheless, some older children may be reluctant to start at the very beginning of Story Mode as they consider it to be "too easy" for them or a waste of time.
In these situations, you can turn off certain maths topics which you are certain the child is fluent at. They will then be able to skip these levels in Story Mode.
To turn off levels which relate to certain topics in Story Mode:
Go to "Manage Users", then click on the name of the child.
Go to the final tab, "Settings".
Under "Select maths topics to exclude from Story mode", turn off the topics you do not want them to practise. The changes will save automatically. Please ask the children to log out and log back in in order for the changes to take effect.