On Thursday the children used different types of cups (Styrofoam, plastic and paper) to find out which could hold their weight. They worked in groups, placing different numbers of empty cups in varying arrangements and then testing to see if it could hold their weight as they walked across.
Here are some of the predictions, observations and comments from the children.
What will happen if we stand on the Styrofoam cup?
“It will break.”
“It will squish.”
“It will crumble down.”
What will happen if we stand on the plastic cup?
“It won’t break because it’s hard like wood.”
“It might have a crack.”
“It might fall down.”
What do you think about the paper cup?
“It can easily rip.”
“It’s too soft.”
“It’s stronger than the white (Styrofoam) cup.”
How can we get the cups to hold our weight to walk over the ‘bridge’?
“We can use lots of cups.”
“Let’s take four. And put them on the corners.”
“We need more.”
“I think we need sixteen.”
“Eighteen is enough.”
“Put four at the sides.”
“I think it’s stable because there’s more cups.”
“I want to put them on the corners. It will be more stable.”
“Six cups will be ok. In a rectangle.”
“I have a great idea. Let’s use all the cups. The plastic cups, paper cups and squashy cups.”
“Put them on the edges so it won’t fall.”
“Spread them out.”
“Get cups all the same height.”
“We can’t use a cracked one.”
What did you see happen when we tested the cups?
“It stayed up.”
“When we put them in a circle it was only strong in the middle.”
“The edge flipped up.”
“The board spinned and flipped.”
“It didn’t collapse because we walked on it slowly.”
“When we put them in the corners it was strong.”
“The white cup at the end got squashed a bit.”
“It collapsed when he stood on the edge but not when he stood in the middle.”
“It didn’t collapse because we used more cups.”
“It broke when he jumped on it.”
On Friday, we returned to the sand mixtures to test which ones could withstand the weight of a block or water. As the children carefully turned their cups upside down some mixtures held firm while others were not so stable. Nonetheless they all tested them by watering them to see if they could retain their shape in a rain shower. The next test was to see how many blocks each sand castle could hold. The children noticed that those made with greater quantities of glue were the most successful at retaining their shape and holding more blocks.
It was a lovely opportunity for the children to learn about how different materials behave and can be used in different ways. It also gave them a chance to use scientific methods of prediction, testing and reviewing results. In science, it is often the results that we don’t want or expect that teach us more. By realising that their foundations were not strong or weatherproof the children initially felt a sense of disappointment, but these situations created the more interesting discussions and requests to retry.
We are very grateful to Mrs Asif for sharing her time and expertise to give the children this experience.