A jar contained some pebbles. Nigel took out half of them plus 2 more for display. Jenny took out half of the remaining pebbles plus 1 more. Finally,
If you do use algebra (of some sort), remember to use different letters e.g. v, w, ... etc to refer to different things. Likewise, do not just write ‘½’ to represent ½ a unit, otherwise it could be misinterpreted as literally the number ½. I suggest you can surround the ‘½’ with different shapes (e.g. circle, square, triangle) .