Looking for a way to differentiate and challenge without any significant need for resources?
Try out ACE questioning. A simple idea which can have big results.
I use it several ways dependent on the class and learners ability range.
A = accept
C = challenge
E = extend
The teacher asks a student if they would like to accept, challenge or extend the answer of another student. The student decides and does one of the above, ensuring that if they accept they explain why.
The teacher asks selected students certain questions related to A, C or E.
e.g. do you accept what child A said, why/why not?
During peer assessment students state whether they accept the work as it is and explain why, challenge the answers given by asking them a question such as why do you think… or I actually think this… can you explain why you’re right? Or they ask a question to extend the answer given.
Try it out and let me know how it goes.