Ah stitched
It's no help at all - but welcome to the club - our school was like this until this year (Ofsted is coming) and I suspect will return to form once Ofsted is over.
First off: Government guidance on homework here:
www.direct.gov.uk/en/Parents/Schoolslearninganddevelopment/SchoolLife/DG_179508
Year 4 - They recommend 1.5 hours a week, but they don't specify in what. To be fair, the balance may depend on the situation - if you have a strong reader, but weak in maths, you might want to spend more time at home shoring up maths understanding than working on reading. So I suppose the division/ emphasis on what to work on is down to you.
There's also a nice guide with tips on how to support homework here:
www.direct.gov.uk/prod_consum_dg/groups/dg_digitalassets/@dg/@en/@parents/documents/digitalasset/dg_187190.pdf
Basically I support by DDs by concentrating on the 3Rs -
Reading: Reading out loud with them
I still read to them - but select classics that they might
not tackle yet but are good stories (e.g. Charlotte's Web,
Treasure Island, etc...)
Look into recommendations on reading (as there are a lot of
great new authors out there).
Some useful websites:
book trust list of books for children by age group:
www.booktrust.org.uk/books-and-reading/children/
The Guardian had an excellent insert about how to build a great library of books for children: www.guardian.co.uk/books/series/building-a-children-s-library
Kidsread has a 'classic' book list by age & reading ability here:
www.kidsreads.com/lists/classic-lists.asp
Finally with reading - it can help shore up other subjects in school - particularly science and history by reading more about an interesting topic. Libraries are brilliant for this - either public libraries, school library or class library should have a good range of non-fiction books/ children's encyclopaedia's (which are much better than in my day - many more interesting diagrams and photographs & all in colour now!). The internet can be really useful for this as well - although you may want to start your search through or on a trusted website: BBC, Discovery Channel, National Geographic Kids, etc...
-------
Maths
Kind of depends on your situation. If your DC is struggling you may want to consider signing up to on-line tutorials to give them the opportunity to learn at their speed and get in practice. I've signed up to Mathsfactor for my DDs, but DD1 was seriously struggling. I hasten to add you have to pay to join something like this - so you do need to weigh up whether this will work in your situation and whether you can envision sticking with the tutorials after a few months.
If you would like a bit of practice to encourage mental maths - I'd highly recommend Tux of Math Command. It's free. It's an open source video game based on the Asteroids format. You can select the skill level and the type of maths problem you want to review and basically sums come down the screen and you blow them away by typing in the right answer.
You can download the programme from here: tux4kids.alioth.debian.org/tuxmath/
The BBC has set up a learning website in BETA (so trial stage) here:
www.bbc.co.uk/learning/
This gives you direct access to teaching materials by Key stage and to BBC Bitesize.
If you select Schools on the right and then Teachers on the right - you can then select otpions from KS1 or KS2 as appropriate from the menu box midway down on the right. Now this lumps together all years - but at least gives you a good idea of what's avaialble. I find if you have a go yourself, you can pretty much judge whether you DC is ready for this or not.
In the menu box mid-left - you can select which topic (so say maths) and then the yellow tabs above let you select the appropriate Key stage. From there you get a list of topics (which you can click) - but there also are tabs for resources, activities and games.
To the right of the menu box on the schools or teachers page - is the Bitesize review games - this is geared up for preparing for SATs but has a lot of great games which can help tackle those little niggles and give good practice.
Cooking can be a great way of learning about time, weights and measures and is lovely time together. Teach them about reading a clock (digital or analog) to work out what time it will be when the cookies are ready. Have them weigh or measure the ingredients - to develop a sense of scale for these standard measurements. Talk about metric and imperial system of measurements.
From about Y3/Y4 - you can also have them calculate the change when you pay for things. So have them notice what a small bit of shopping totals and then ask them to work out what the change should be. Or play the game as you shop. If I have £1 and this can costs 74p - how much change will I get?
-------
Writing
Our school provides no homework on this at all, aside from the reading diary, which can be as little as saying 'I read a chapter'. So, I try to encourage as much as possible by sly.
Thank you cards (after birthdays, Christmas, special treats/ visits) are a good way of getting practice in.
I also have them write postcards whenever we go on holiday. Have them send postcards to their teachers, to their grandparents, to their friends, etc...
I get them to write in to competitions. Not just do the drawing, but write to the magazine or book about why they like it (The Rainbow Fairies for example has lots of competitions for girls - I'm sure there must be something similar for boys series' I just haven't come across it yet).
That transition to writing more than a few short sentences (my DDs are in Y2 and Y4) is still eluding me, but I'm starting to get DD1 (Y4) to write alternative endings or discuss what she would change about the books she's reading in her reading diary. She's currently written 2 acts of a play about a fairy tale. This all started from reading a rather easy book to her younger sister, but she's set out the actors played by her classmates, the props, etc... and has written about 10 pages in her reading diary. It really has captured her imagination.
------
Learning when you least expect it:
Learning can also happen on holiday, outings, etc...
Have the children read signs at historic places or museums. Ask them to spot a Greek myth or bible story in the paintings in an art gallery. Ask them to find an object from Jurassic period in a natural history museum/ of section of a museum.
Get the guidebooks and have your child decide what to see and where to go.
Let them try and draw a copy of a painting or sculpture you visit (either there and then or from a photo).
Talk to them about your sports heros. If you DS is wild about some footballer now, talk to him about the footballers you admired as a kid and what they went on to do.
Talk to grandparents about what life was like when they were little or during World War II. Actually just talk to grandparents. They both love it!
Anyway I hope that helps stitched. You're not alone - a lot of schools don't provide much in the way of homework. To be fair if you google homework you'll learn fairly quickly that in primary school there is a lot of division about whether it is a good thing. However, it is clear from secondary school good study habits make a definite positive difference in terms of achievement.
However - primary children are just that - children - and they can learn as much by lying on their back and watching clouds and bumble bees drift by as they can reading a book. They also need time to imagine, develop phsyical skills and time to just muck about and day dream. That's important too!
Hope that helps