Doubling and Halving numbers to 50.

As part of our mathematics work children worked in groups to double and half numbers to 50.  They discussed the strategies they could use, especially for halving odd numbers. 

One strategy that the children suggested for halving a number like 23 was to go to the even number before (22) half that number first, then half the remaining 1.  Finally add the 11 and 0.5 to find the half for 23.