Marshmallow Challenge

Backgrounds

Our economic teacher organized a game called Marshmallow Challenge in her class after we finished CAIE international examinations. In this game, students worked in groups (a group had 4 students) to build a tower by using marshmallows and sticks. Our teacher would measure the height of tower and gave students tokens (1 mm= 10 tokens). It is worth mentioning that the marshmallows and sticks were charged. The first 1o marshmallows were free, but others were charged by 20 tokens per marshmallows. And each stick needed 10 tokens too.

What our group did

When we got marshmallows and sticks, we first measured their length and found that the cost of marshmallows and sticks was quite low compared the tokens you could get if you build a higher tower. As the diagram showed, you just needed three extra marshmallows and six extra sticks to enlarge the tower. (Each stick was 5 cm long, in other words, you could 500 more tokens while only pay for the cost of 120.)

So we(members in our group) built the tower together and asked our teacher to measure its height. It was 25.5 cm tall which was the tallest in our class.

Here is a photo to record our achievement.

Analysis–why we could build the tallest tower

Cooperation

We performed well partially because we cooperated with each other excellently. Each member in our group did tasks positively, we tried our best to think ideas and gave others advice through the efficient communication. For example, one of us advised to build one layer of the tower then combined the tower and its new layer through sticks, it could make sure our tower is solid enough.

Besides, when we felt that our tower would topple down, we would try our best to reinforce it.

Scientific design

We used a scientific way to design the structure of our tower. Actually, we were asked to draw a poster to introduce our tower. And in this poster, we enumerated some advantages of our design.

This is our poster.

This is our marshmallow tower.

1. Triangular structure: We have already mathematic trigonometry knowledge in primary school or secondary school. Triangular structure is the solidest structure.

2. Bearing： We used two bearings to reinforce our tower efficiently. As we know, the base was important for a tower. It would topple down by the turning effect caused by the weight.

(Simple physic knowledge, you could even find it in IGCSE physic book.

Teachers’ summary– what economic knowledges we have learned from this activity

Fixed cost and variable cost

In this game, the cost of marshmallows and sticks changed as the number of them we used were changed. In other words, the cost of them were variable cost. Meanwhile, the cost of hiring workers (we were workers) to build the tower remained the constant, so it was a kind of fixed cost.

Diminishing marginal benefits

We may find that it is easy to build the first layer of the tower. However, as the tower enlarged, you may find that it is much more difficult to add an extra layer. You needed to add bearings to support the base. In other words, with the same marginal revenue (one layer of the tower means a fixed value of extra height and thus get the tokens). the marginal cost increased the marginal benefits diminished.

The prize– we were winners

Students who built the tallest tower would get a badge. There were four types of badges (all of them have contents related to Economics on them) to choose. I took a picture of my badge. The “MC=MR” stands for marginal cost equals to marginal revenue, which is an economic concept for profit maximization.