As many will know doing more at home has been very beneficial to DD1 (finishing NC L1 across the board end KS1/ going on with regular homework provided from parents (not school) to achieve NC L6 Maths/ NC L5 English & TA assessed Science).
Now this is actually what the educational endowment says on primary school homework (as opposed to mrz's version): educationendowmentfoundation.org.uk/toolkit/homework/
in particular they say: There is some evidence that when homework is used as a short and focused intervention it can be effective in improving students’ attainment (with some studies showing up to eight months positive impact on attainment). Overall the general benefits are likely to be modest if homework is more routinely set.
However if you look at the references - there are 6 studies - two of which are reviews of the previous data. So I'm no persuaded that this has been seriously studied - moreover structurally these studies link homework to schools' overall achievement - and does not follow individuals.
So in fact the data on whether giving a FSM child regular access to reading material and possibly computer time for maths games, etc... before/ after school might be of benefit or not simply ISN'T there.
I remain a firm believer that practice helps regardless of what you practice...
be it a musical instrument
a sport
drawing
painting
or heaven forbid
even mathematics.
In our case with a child who sincerely could not take 1 from 10 by May of Y2 - I can say hand on heart that doing more at home made a huge difference.
Issues like noisy classroom/ distractions/ poor instructions/ poor explanation could be avoided by doing things at home. Initially I had to give a lot of support whilst she used an on-line maths' tutorial - but soon DD1 just got on with it herself.
DD1 finished Y2 at NC L1 in Maths on KS 1 SATs.
DD1 finished Y6 at NC L6 in Maths on KS2 SATs.
Maybe it was homework/ maybe it wasn't.