If you're looking for a flexible system there are website like my math (www.mymaths.co.uk) however if you are looking for a tutor you will need to spend some money. I recommend top tutors (http://www.toptutors.co.uk/?gclid=CLKJjP2k9q8CFRQrfAodmE7eEA). They have been established for 27 years and are well experienced.
Perhaps math lessons wouldn't be suitable for your son, as you could easily help by reading this teaching guide I found on a very reliable site! http://www.edu.gov.on.ca/eng/literacynumeracy/parentGuideNum.pdf
No matter what grade you're in, you can find the math lessons you need at the Mathfoundation. I used them althroughout high school. You can find them online.
I totally get wanting to find fun math lessons. Keeping kids engaged is half the battle. I usually check out YouTube channels like Numberphile for cool concepts and Prodigy for game-based learning. For structured practice, Beestar has been great. It mixes engaging challenges with a structured approach, so my kid stays sharp without feeling overwhelmed.
There are countless websites that offer all kinds of various lessons for young people. You can go to the website Enclypediabritanica.com in order to find out more about these lessons.
You need to average 9/3 = 3 math lessons per hour.
You do Lessons!
son-less: i.e. having no son
webparent.com/math directly deals with sucessmaker math. It links to websites that have learning opportunities and learning games to help your son improve his math skills.
Teaching children math at home can be a very difficult thing for some parents. You can visit the website www.homeschoolmath.net/ for step by step instruction that will help you learn to teach them math.
My kids find hoddamath.com and mathplayground.com helpfuly in teaching them math. It also improved their math scores at school.
There are websites who will help you increase your math abilities. Also, there are many people who will tutor you. Contacting a local high school can help you connect with a tutor who could provide math lessons.
You can find math puzzle worksheets for your son at mathriddlebook.com,softschools.com,mathgames4children.com,mathrealm.com,worksheetworks.com,mathis fun.com.