So - Ds1 and I know that the median is the middle number. DS has been taught to order the numbers given and then work inwards, putting a finger on each outer number and moving in. But if you have the numbers 3,2,9,10,12,2 for example, do you count both twos?
If you do, we end up half way between 3 and 9. So is the answer 6? He is blithely writing 3.5, but that can't be right, surely?
If you only count one 2 the answer would be 9 -