Recently I have been planning a lesson on the classic exam situation of completing a partially complete two-way table, such as this one:
Now in my experience pupils grasp the concept of this quite quickly, with most mistakes tending to come in making arithmetic errors rather than mis-understanding the problem. Which of course leads me to the problem of how to stretch the lesson for those pupils who do grasp the concept so quickly.
During an internet trawl for inspiration I came across an excellent resource from the brilliant team over at JustMaths, which has 5 tables to complete (enough to give enough practice at arithmetic) that are all linked together and then provides an interesting activity whereby pupils have to identify which teachers are making mistakes in analysing the resulting tables. It was then that I had one of those nice ideas which occasionally occur to me; here was an ideal moment to link in some prior learning!
Taking the JustMaths tables I then created some statements that go a little beyond their "True or false" on the back, into True/Maybe/False. I brought in these statements:
1) Every student studies English
2) Every student studies Maths
3) More students study Food than Biology
4) A greater proportion of students study Biology than Food
5) The ratio of Boys to Girls studying Art is 2:1
6) More than 80% of the students studying Applied Maths are boys
I won't spoil the surprise of the resource by telling you which are True, which could be true and which are false, but the answers are in the lesson here if you desperately have to know; needless to say there is at least one of each.
Now you may not use the Just Maths resource, you may not use these statements, but if you are looking for a little stretch in your two-way tables lesson, try bringing in some other prior learning number statements, and trying setting some statements that are definitely true, could be true or definitely false.