IXL Maths is a subscription (paid) maths site that has some structure, but also a lot of flexibility. I have been using the UK version, so the description below reflects that, but it also has editions for the US, Australia, Canada, Europe, India, Ireland, New Zealand, Singapore and South Africa.
The site is update to have all the materials grouped by the relevant school year according to which country you’ve picked, and seems to be updated quickly when the national curriculum changes.
I would describe the content as semi-structured: the topics are ordered within the year and you could work through them in order if that made you comfortable. However, you don’t have to do this: no matter what year your child is, all the years and topics are available. It’s well organised: the years are ‘folder tabs’ along the side/top of the page, and clicking on one takes you to the topic list for that year. You can then scroll through the topics and pick the one you want.
Within each lesson, the structure is fixed: the child is given a series of questions. Getting them right increases his or her score, getting one wrong decreases it. The child has to get to a ‘Smart Score’ of 100 – but that doesn’t mean answering 100 questions! I’m not sure what the algorithm is, but you get higher scores for getting several answers right in a row, and lose more or less marks for getting questions wrong. Whatever the rules are, they seem to be a fairly good measure for my son of whether he knows the topic or not. YMMV, but I like the approach.
There is no fixed order that you have to approach the topics. Your child can start straight in at their current level, or work their way through from the beginning, or dip in and out of various topics on different days. The choice is yours.
There are no ‘lessons’ to work through. Choosing a topic starts straight in with questions. However, if the child gets one wrong, there is a thorough explanation (with diagrams) of what went wrong and how to do the question. It’s also worth noting that as a parent, you have access to all the exercises too through your login, but that any questions answered as you don’t affect the child’s scores. So if your child (like mine) hates getting questions wrong, you could always do 2 or 3 ‘demo’ questions with your login switching to the child’s login and letting them try it for themselves.
IXL doesn’t have the cutesy videos and cartoons that some other sites have. However, there are awards and certificates for various achievements: skills mastered, time spent, number of skills in a particular topic area, etc. Each year has a theme for the awards: Year 4 is the Wild West, and the awards are a coach, a cactus, etc. There are also printable certificates.
Overall, IXL has just-enough fun factor for our family: the lack of cute cartoons and animated graphics is balanced by the fact that my son can skip about and follow his own interests, which makes doing the maths less of a chore.
Cost varies, depending on whether you pay monthly or yearly, and whether you want just maths or maths and english. I find the cost reasonable, but that’s a choice that each family needs to make for themselves.
This is our family’s maths site of choice, but which site suits you will depend on various factors, like the child’s and parent’s level of confidence, preferred learning style, age, etc. I’d definitely recommend trying out IXL and seeing if it suits you.