I added in my guess of 2500 and we reworked our range and averages to see the effect - this led to us agreeing to use the median rather than the mean.
To introduce stem and leaf we discussed the pro's and cons of their own tables, then I asked someone to read out the data and completed a stem and leaf on the board as the data was read out - pupils were then asked to explain how it worked, they could easily work this out from watching me complete it but they all followed much easier than when I have taken the time to explain what I am doing. We redid the dots experiment (by which point they were desperate for the answer), then we compared our answers using the range and median. Finally they were given the result - our second guess was closer and with a lower range. Pupils were able to demonstrate a good understanding of both terms (beyond it's the biggest take the smallest)
'How big is a cow' is to cement the work on stem and leaf and to get some levelled work in the books (peer assessed). To do 'how big is a cow' I show the class a normal cloth and ask them to write down how many cloths it would take to go from head to the back end of a cow. We record the data in a stem and leaf, discuss and then take 2 volunteers to be the head and bum and we measure out our cow. Every time I've done this the cow is usually too big to fit in the room.
Boys V Girls on staring competition, record the data on a 2 way stem and leaf, compare boys results against girls, complete a written summary and peer assess.
how_big_is_a_cow.notebook |