At KS3 we recommend 3 topics per week on average.

At GCSE we recommend 6 topics per week on average.

If you set a shorter homework (e.g. 30 minutes as opposed to 60 minutes) you may wish to reduce the number of topics so that students still have enough practice on each set topic.

You can use the Preview feature in Planner to see what questions will be set for different lengths of homework and numbers of topics.