Year 2 Science Uses of Everyday Materials – Block 2UEM – Squash, bend, twist, stretch

Session 3:Testing rigidity
Science curriculum area(2UEM): / Content(2UEM)
i. identify and compare the suitability of a variety of everyday materials, including wood, metal, plastic, glass, brick, rock, paper and cardboard for particular uses
ii. find out how the shapes of solid objects made from some materials can be changed by squashing, bending, twisting and stretching
Working Scientifically (KS1 WS)
- skills explored withguidance / Working Scientifically (KS1 WS)
i) asking simple questions and recognising that they can be answered in different ways
ii) observing closely, using simple equipment
iii) performing simple tests
iv) identifying and classifying
v) using their observations and ideas to suggest answers to questions
vi) gathering and recording data to help in answering questions
Teaching Objectives /
  • To understand that some materials need to be able to 'give' a little and not break (for bridges carrying heavy traffic, for example)
  • To look at a selection of materials and discuss how they might be tested for their rigidity
  • To devise an investigation to test the flexibility of materials (by hanging weights from string onto the end of each strip of material)
  • To make predictions and carry out the investigation, recording the results

Key Vocabulary:squash/squashing, bend/bending, stretch/stretching, material, properties, strong, weak, rigid, flexible
Resources
Images of bridgesand vocabulary cards from resource,a selection of materials for each group, including lengthsof wood, metal, plastic, card (Make them similar lengths: you could use plastic, metal and wooden rulers), small weights (100g), tape, string. / Weblinks
Before the session:Collect a selection of materials for each group, including lengths of wood, metal, plastic, card. Try and make these similar lengths. You could use plastic, metal and wooden rulers.
Whole class:Show the images of bridges and their materials from the resource. Ask:Has anyone ever been on a bridge like these? The ones with the metal ropes are called suspension bridges and they are designed to move a bit. Do you know why? (So they don't break when the wind blows, or when traffic is heavy,etc.) Show the chn the selection of materials you have collected. Hold them up and ask for a volunteer to list them in order of rigidity (from 'not at all bendy' to 'really bendy'). Ask the rest of the class if they agree and to explain their choices. Then set the chn a challenge by saying: You are all now really good at doing investigations and thinking like scientists. Your challenge for today is to investigate the materials to see how bendy they are. The items available to you are some weights, string and tape.
Activities:Split the chn into groups and give them time to think about their experiment. Move around the groups, keeping them focused on the need to test the bendiness of the different materials. Let them explore their own ideas but if they get stuck, suggest that they tape down the strips onto a table edge so they lie horizontally, then to use the string and tape to secure a weight on the end of each strip. Remind them that the weights will need to be the same and so, if they don't have multiple 100g weights, they will need to measure the bendiness of one strip of material, then remove the weight and attach it to the next strip.Ask them How will you record the bendiness? They may want to attach the strips to the part of a table closest to a wall so they can attach paper to the wall (directly behind the horizontal strips) and draw the bend produced.
Plenary / When the groups have explored what happens when they attach weights to strips, ask them to come together and discuss their findings. Ask them What have you discovered by doing your investigation? How shall we record our findings? You may want to do this by video recording the chn speaking about their work, or through a series of small annotated drawings (draw each strip and the bend produced). Ask the more able if they can work out what the results would look like on a bar chart (title: bend with a 100g weight, x axis = type of material, y axis = amount of bend in cm).Then place the word cards from the resource sheet in a bag or spread them face down on a table. Ask chn to come and choose a card and read it to the class. Ask chn from the class to offer explanations about the meaning of the word. Discuss those meanings and together decide on the most accurate. Write that meaning down on a strip of card and display it, with the word, in the classroom as part of a large collective vocabulary display or dictionary.
Outcomes / Children will
  • Understand that some materials need to be able to 'give' a little and not break (for bridges carrying heavy traffic, for example)
  • Explore a selection of materials and discuss how they might be tested for their rigidity (identical lengths of wood, plastic, metal, card)
  • Devise and carry out an investigation to test how much they will bend and discuss the results

© Original resource copyright Hamilton Trust, who give permission for it to be adapted as wished by individual users.

We refer you to our warning, at the foot of the block overview, about links to other websites.