http://www.amazon.com/Help-Your-Kids-Math-problem/dp/0756649...

http://www.amazon.com/Math-Power-Child-Dover-Mathematics/dp/...

http://www.amazon.com/What-Help-Child-Math-Myself/dp/0974168...

Amazon.co.uk

http://www.amazon.co.uk/Help-Your-Kids-Math-Problem/dp/07566...

http://www.amazon.co.uk/Math-Power-Child-Dover-Mathematics/d...

http://www.amazon.co.uk/What-Help-Child-Math-Myself/dp/09741...

My favourites are the Rob Eastaway / Mike Askew books:

http://www.amazon.com/More-Maths-Mums-Askew-Eastaway/dp/0224...

http://www.amazon.com/Maths-Mums-Dads-Rob-Eastaway-ebook/dp/...

http://www.amazon.co.uk/Maths-Mums-Dads-Mike-Askew/dp/022408...

http://www.amazon.co.uk/More-Maths-Mums-Dads-Askew/dp/022409...

(Amazon: Please have some really easy way to give me a clean url for sharing. I am literally sending potential customers to your website.)