How many peas?

If you are ever looking to do a functional activity that looks a volume and brings in lots of other maths then this is a project for you.
I did this lesson with a year 8 set 2. They had already spent a lesson calculating the volume of lots of different 3D shapes but needed to think about applying their knowledge to a real life problem.




The starter consisted of pupils approximating how many peas they thought would fit inside our classroom. I gave them a prompt, which was a picture of our classroom and a bag of peas. They had to guess how many peas would fit inside our classroom.

The pupils decided that they needed to know the dimensions of the room, the size of a pea and if we were keeping the furniture in the classroom. They decided that they would remove all the furniture.
I gave them a piece of card, a piece of centimetre squared paper, glue, Sellotape and a small cup of frozen peas.

I also gave them 5 minutes to discuss as a pair what they were going to do before I let them have any equipment.

After the 5 minutes we had a class discussion about what would be the best method to approximate the number of peas inside our classroom.

Some pupils wanted to use the Internet to find out the formula for volume of a sphere so they could model the peas. This was a great idea but my pupils decided that there would be lots of gaps in between the peas and after many debates they said that they wouldn't be able to work out the volume of those gaps.

Some students wanted to make a scale model of the classroom and fill it with peas. One student even wanted me to buy as many peas of possible and actually fill the classroom, but lucky the rest of the class explained that this would be a silly idea.

The class settled on an idea and they all made a scale model of the classroom and filled it with peas. They made it initially with squared paper before using the card. Just before the end of the lesson the pupils had counted how many peas fitted inside their model.

They then needed to think about the scale factor, which caused some confusion.

For homework they wrote up their plan.

At the start of next lesson we took together all the pupils results and discussed what we were going to do with them all (there were 16 results in total).
The class spent 5 minutes discussing as a pair and completing some calculations.

After the discussion we had a class discussion and they talked about different kinds of averages and which one would be best to use.

The whole task only took about 1 hour and 15 minutes but it was an extremely rich task that looked at a variety of topics such as, Volume, Scale Drawing, Averages, Scale factors and Nets.

It also allowed the pupils to work in a group and develop their problem solving skills as well as their ability to deal with a set of real data that they created.

An AMAZING lesson which the pupils will never forget, even if I was still finding the odd pea a few weeks later!!