Hi, I'm a student teacher and I'm being observed for a lesson teaching y3 children to round 2 or 3 digit numbers to the nearest 10 or 100. They also need to be able to give estimates for their sums or differences. I think I'm being a bit silly, but I don't understand what the estimating sums and differences means...it's Sunday, my brain is dead from a weekend of planning and the national strategies have left me panicking. Can someone enlighten me? I also can't seem to think of a way to make this maths interesting and more 'real'. I love teaching active lessons and the children really enjoy this, but I'm struggling to think of a way to make this happen in rounding. Can anyone suggest anything? Thanks so much in advance.