Today I told the children that I thought our new area in the woods might be smaller than our original site and I asked them to go and sit down in their groups and work out how we could measure the two sites. I took trundle wheels, metre sticks, string, calculators and clip boards with squared paper on.

After a few minutes I gathered the children again and they suggested that we could measure a single length, the perimeter and the area. They identified that we needed to define the ‘boundaries’ of our area and children took it in turns to walk the boundary and we agreed on a common theme. I persuaded them to think of the site as a square/ rectangle, we haven’t learnt how to find the area of a circle!

I sent the children away again to decide exactly how they would measure the site and then they set to work. There weren’t enough trundle wheels so one group ( the most supported) just used string to measure the perimeter and then measured the string with metre sticks.

One group  decided that the area was actually made up of squares, rectangles and triangles. BA  explained to the others how to calculate  the area of these shapes and they drew a detailed diagram and set about finding  the required measurements.

We discussed that there was no need to measure in cm ( and even mm!) as our measurements were very approximate.

One group used a tally chart to help them keep track of the trundle wheel ticks (EW).

Most groups found the area of a square space. Two groups measured the perimeter then divided that by 4 to find a square edge measurement which they then used to calculate the area. I drew a few pictures to remind them that shapes of the same area perimeter can have different areas etc.

I challenged early finishers to find the tree with the biggest girth – we all estimated and the answer was surprising ( 2.5m).

I asked the children to think about what they will do differently next time and most had a clearer idea about how to proceed. I will try to find another trundle wheel.