Not wishing to digress too much, but my "Superstar grade A" son at a reputable international school here is struggling at age 8 with maths I could do age 6. I've enjoyed spending more time with him on this than just reading bedtime stories, etc. I'd say he can still do the papers I linked here, but maybe just 80-90% pass rate, if I threw him the 8 year old papers, probably around 60%.

I recall doing test papers from the 60s when I was at school in the 80s, and they were damned near impossible even for the best student in the class (not me!), so I'm looking at this with an open mind that the education system really is starting to fail kids in the pursuit of "participation medals" and not offending anyone that their kid is actually daft as a brush. Anything that is hard, or the weakest of the pack can't do is shunned. So it is definitely worth keeping an eye on here, if my son was to sit the 11+ in the UK, he'd struggle as it stands I think - unless the test has become easier in the last 20 years (likely?). But ignoring passing tests at whatever level is there for the plebs, I think we need to strive for greater things as parents, so I'm knuckling down on the little guy to get him at the level I was at - he's super bright, and doesn't shirk the challenge. I'd implore other parents to look carefully at this as the OP does - well done sir - sure little Johnny (not walker! ) may be a superstar at school here, but check in on them & be directly involved in their education where possible.