Here are two examples.
1) Under algebra, children (the curriculum prefers to refer to them as 'pupils') in Year 6 are required to learn how to
· find pairs of numbers that satisfy an equation involving two unknowns
but nowhere are they required to find solutions to equations with one unknown!
2) In learning about geometric transformations, children will meet the concept of 'rotation' in Year 2, but then the word does not appear again in the primary curriculum. So, after Year 2 there's nothing at all about recognising and describing a transformation of a shape in terms of rotation and there's nothing anywhere in the curriculum about rotational symmetry.