http://i48.tinypic.com/2dt0hfc.jpg\">Attached a school marking gudeline.I personally feel Pupil B deserve the working marks. The vertical working shows that the child has understood how to solve the question , and i see it the same as the number statement. it should be also acceptable if the vertical working is shown just above the number statement.Though i would still encourage my child to follow the guideline, strictly penalising a pupil for this might demoralise the young child.