GoalPredict and test which material makes the strongest paper bridge, and record the result in a table.
New words
test · to try something out to find an answerpredict · to say what you think will happen before you testresult · what you find out in a test
Explanation
Mia wants to know which material makes the strongest bridge. She makes three bridges, one from newspaper, one from thin card and one from a plastic sheet. Each bridge is the same size and goes across the same gap between two books. First she predicts: I think the card will be strongest. Then she adds coins to each bridge, one at a time. The strongest bridge holds the most coins before it sags down and touches the table. She writes the results in a table.
Bridge material
Coins held
newspaper
4
thin card
12
plastic sheet
7
Worked examples
Mia tested three materials: newspaper, thin card and a plastic sheet. Her card bridge held 12 coins. It was the strongest, so her prediction was right.
The newspaper bridge held only 4 coins. It was the weakest.
A block graph shows the same results. The tallest block is the strongest material.
Class activity
Bridge test (with an adult): stand two books about 15 cm apart. Make bridges from strips of newspaper, thin card and a sheet cut from a plastic folder (an adult cuts them to the same size). Predict which is strongest. Lay each strip across the gap and add coins one at a time. Write how many it held in a table.
Practice
1
Kenji did the same test with other materials. Which bridge was the weakest?
Bridge material
Coins held
foil
5
thick card
15
kitchen paper
2
The kitchen paper. It held only 2 coins.
2
Look at Kenji’s results. How many more coins did the thick card hold than the foil?
10 more (15 − 5 = 10).
3
What does ‘predict’ mean?
To say what you think will happen before you test.
4
Ali predicted that Mia’s plastic bridge would hold the most coins. Was he right?
No. The card bridge held the most (12 coins). The plastic held 7.
