Comparing the Strength of Paper Column Shapes
About this lesson
Children roll and fold scrap paper into round, triangle and square columns, predict which is strongest, then stack books on each to find out. They practise making predictions, running a fair test and explaining results about structures. You need scrap paper, tape and a few similar books. It takes about 15 minutes.
- Grade
- 3
- Subject
- Science
- Time
- 15 min
- Prep
- 3 min
Objective
Students will test and compare how column shape affects strength, and explain why a round column holds the most weight.
Prep
3 min: draw a results table on the board with columns for round, triangle and square
Materials
- scrap paper (same size, 3 sheets per group)
- tape
- 5-8 similar-sized books per group
- whiteboard
Steps
- Put children in groups of 3 or 4 and give each group three sheets of paper and some tape. Show them how to make three columns of the same height: roll one into a tube, fold one into a triangle and fold one into a square, taping each seam.
- Ask each group to predict which shape will hold the most books and write the prediction on a scrap of paper. Say, 'To keep it fair, we use the same paper, the same height and the same books.'
- Have groups stand one column on the desk and gently place books on top one at a time, counting until it crushes. Repeat for the other two shapes.
- Collect each group's counts in the board table and look for a pattern. Ask, 'Which shape was strongest every time, and why might that be?' Explain that a round column has no weak corners, so the weight is shared evenly all the way around.
- Finish by asking children to name a real structure that uses round columns, such as pillars, table legs or tree trunks.
Quick Check
Each child tells a partner which column shape was strongest and gives one reason using the word 'corners' or 'spread'.
Differentiation
Make it easier: Make the three columns ahead of time so groups only predict, test and count.
Make it harder: Have groups change one thing, such as making a shorter column or using two sheets, then predict and test whether it holds more books.
Good For
- Before lunch
- End of day
- Supply teacher
- Review
