Hi threescoopsundae:
I had real troubles with DD1 in her first few years of primary school - she just quite simply couldn't add above numbers to 20 and couldn't subtract at all (up to May Year 2).
Our solution was trying different things until we came upon something that made sense to her.
In our case it was mathsfactor (www.themathsfactor.com/) - which had the advantage of being presented by carol Vorderman - a video lesson where the ever cheerful Carol explains a concept. A little practice exercise/ warm - up and then 10 - 30 problems reviewing that concept. It's good old fashioned learning through watching someone do it and then trying it yourself. But dividing it up into bite sized chunks and teaching the concept really helped make sense of maths skills for DD1 - who was not responding well to quizzes, fill-in the blank multiplication squares/ number squares, etc...
There's a ton of on-line support out there and many boys respond well to gaming platforms and therefore don't mind 'practicing' maths skills in that format:
FREE websites:
Woodlands Junior Maths Zone: resources.woodlands-junior.kent.sch.uk/maths/ - just select the area you want more practice in/ to work on and follow links to resources. A bit of a hunt to find the right game - but worth an explore.
Cool Maths for Kids - www.coolmath.com/ - a bit clunky - but there are lessons (to explain how to do something)/ games/ resources - all a great help.
Multiplication dot com has tons of games to help bed down those crucial times tables: www.multiplication.com/
Math Champs - has games grouped by ages 5-7/ 7-9 and 9-11. This can make a child feel bad if they're struggling with games allegedly for younger children - but try to gloss over that: www.mathschamps.co.uk/#home
- as mrz has recommended nrich maths is fabulous - but this can be off-putting for students that are still struggling to 'get' core skills - so best to explore once concepts are sound perhaps.
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On-line tutorials also exist.
As I've said Mathsfactor was great for my girls (but may not appeal to a boy).
But there's a lot out there. Several here on MN have recommended/ praised:
mathletics: www.mathletics.co.uk/
komodomaths komodomath.com/
Maths Whizz www.whizz.com/
I think all of these tutorials & mathsfactor (link higher up) - have free trials and information for parents to find out more.
Genuinely - have started with a child who just didn't get it and achieved NC L1 at KS1 SATs in maths - I can assure you that we've found slowly but surely putting in regular practice & regularly playing maths based video games makes a huge difference. It builds confidence & skills and success in class sort of reinforces the desire to get even better at maths.
HTH