Age is a starting point
The guides for three, four and five offer different examples. They do not prescribe what a child must know on a birthday. Use the easier idea whenever it makes the activity more enjoyable. In England, Nursery, Reception and Year 1 are useful context; school stages and starting ages differ across the UK.
Keep a grown-up in the picture
A short shared moment gives you a chance to notice what the child is doing: counting each object once, listening for an ending or turning a puzzle piece in their mind. There is no need to turn that moment into a test. The printable off-screen ideas work with ordinary household objects and do not require an account.
