Three graduated online basic skills tests (but new questions can be generated for each test) based on original PDF basic skills tests from AQA. The tests are just one of many hundreds of excellent resources on the mathsbot.com site which is owned, written and maintained by maths teacher Jonathan Hall.
Each test has nine questions. Each question is always on the same topic but gets more challenging as you move from Test 1 through to Test 3. E.g. Q1 is always addition, Q5 is always fractions, Q8 is always measures and Q9 is always ratio & proportion. Ideal for L1-2 Functional Skills Maths.
These tests were converted from three printable, and very popular, PDFs: AQA Maths Basic Skills Questions for Functional Skills Maths and GCSE. These are still available on the AQA site https://allaboutmaths.aqa.org.uk/basicskillsquestions along with teacher guidance and a detailed rationale for each question (AQA log-in required).