Been a while since I had time to write a blog post!

Today I was doing a fractions refresh with Year 7. I needed to instill the difference between cutting in two and cutting in half. After a quick dash to the village shop at lunchtime I was ready…

Equipment

Jaffa cakes or other easily cuttable food stuff, plate, knife, visualiser (optional)

Instructions

Stage 1: Ask a student to cut a Jaffa cake into two parts with one straight cut. The student then chooses which piece to eat and which piece to give to a friend. Having the visualiser meant the whole class could see it happen. When we did it the first couple of students were nice and cut the Jaffa cake in half. Then some of them cottoned on that they could slice off the smallest crumb and have virtually a whole Jaffa cake to themselves.

Stage 2: This time one student cuts the Jaffa cake and the other chooses the piece. Suddenly there were a lot more identical size pieces being cut

Stage 3: Discussion on the difference in meaning between “Cut into two parts” and “Cut in half”. We had a great conversation on same shape, same area, equal, fair. This was the aim of the activity as we were going to be looking at non-standard fraction diagrams

Genius or insane? One student managed to separate the orange and chocolate from the sponge base in one cut