Cicada Maths

Our challenge was to collect as many cicada shells as we could . . . and we beat all earlier records by collecting 1,769.

First of all, we placed them on a 100s board and then sorted them into tubes of ten to make it easier to count such a huge number.  Next we counted out ten tubes of ten to make larger pots of one hundred. We had to carefully balance ten lots of one hundred to make one thousand.  Some people used the flip chart to show the final number, and other people used the magnetic number boards.

It was interesting to find out that the tubes of ten cicadas actually sounded a bit like cicadas chirping when we banged them together.

It has been very helpful using the cicada tubes of ten to count in tens when we have been working out doubles.

First we counted in ones.

When we had one hundred, we put cicadas in groups of ten.

The 100 frame helped us with our sorting 

This is what 1,769 cicada skins look like!

Some people showed the total on the flip board, while others used the magnetic number frames. 

We also wrote the total on the whiteboard.  We had to change the final total from 1 729 to 1 769
after someone found four tubes of ten  hidden under a table!

The noise we made when we banged the tubes together was very similar to cicadas chirping.

The Awesome Acrobatics used the cicadas to help them solve doubles with tens.