Polly Tullberg found maths-whizz:

• Moderately builds student knowledge“Children are aware of concepts that are not taught at school and make links to them in their lessons. When asked where they learnt they state Maths Whizz.”
• Slightly improves attainment“It can be hard to tell as when working on this at home children often receive help from adults despite constant reminders it is an independent activity. ”
• Slightly reduces attainment gap
• Does not significantly reduce teacher workload“It is one lesson every other week. During this lesson I monitor each child and roam providing assistance when need be. So it does not really reduce workload”
• Does not significantly provide school data“We do not use this data in our school for reporting.”