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Standards-based assessment and Instruction

Science K-2














Will It Bend?

In this investigation, we are going to test many materials for bendability (flexibility). I want you to sort the materials into two groups: those that bend and those that do not bend.

You need to examine, predict, and test at least 8 materials. As you work, ask yourself this question: In what different ways do the materials bend?

Don’t forget to record your findings.

Grade Level

K - 2

Big Ideas and Unifying Concepts

Change and Constancy
Cause and Effect

Physical Science Concepts

Properties of Matter

Mathematics Concepts

Data Collection, Organization and Analysis

Time Required for Task

Approximately 60 minutes


Throughout the year (rather than as a monthly mini-unit in science), my first graders are investigating properties of matter. The unifying concept of Change and Constancy is our larger focus. We began in September with water exploration. The children are continuing to
actively use their senses to observe, describe, classify, predict and to practice using reasoning strategies and recording skills. They will use these skills in their next investigation, exploring how materials can be made weaker or stronger (cause and effect).

What the Task Accomplishes

This investigation demonstrates how the children apply their skills in observing reactions, describing the physical properties of solids, classifying a variety of materials, and comparing the weight and size of the materials. It strengthens their predicting skills through practice
with familiar and new materials in their environment. This task also requires frequent communication with peers in their cooperative groups and with adults who are facilitating observations and questions during the investigation.

How the Student Will Investigate

I will guide the children first by asking them to search through the materials to find something that stretches and something that does not. Next, I will ask them to find something that tears and something that does not. Once I observe that students are able to examine and sort materials, I ask them to look for materials that bend.

We use a large sorting mat to categorize materials that bend and those that do not bend. Then, we discuss the recording sheet that asks the children to sketch at least eight objects they have selected to test, make a prediction for each one as to whether they think the solid material will bend, test the material, and record their observations under yes or no. I will model the use of the recording sheet, guiding them through the first material tested.

Interdisciplinary Links and Extensions


Using standard and nonstandard units (and various measurement tools), students can predict, measure and record units for solid objects.

Socia Studies/Language Arts

Cooperative groups can pretend to be manufacturers,
deciding whether certain objects are best made with materials that do or do not bend. For example, would paper, wood, metal, plastic, cloth, rubber or glass be best? Why? Suggestions for objects: basketball, Nerf ball, pillowcase, desk, knife, checkers, hair bands,
magnifying lens, etc.

Physical Education/Movement

Children could bend their bodies to make alphabet letters, pantomime different kinds of solid objects from school or home setting, or locate the most and least flexible parts of their bodies.


Students could explore what allows us to bend our bodies and how bending helps us make work easier and builds muscles. They could also discuss why bones break.

Teaching Tips and Guiding Questions

As the children begin predicting and testing the materials into those that bend and those that do not bend, consider asking these questions to guide their thinking:

  • Which materials do not hold their bent shape?
  • Which materials are the easiest to bend? Hardest? Why?
  • In what different ways do the materials bend?
  • Do all materials bend in the same way?
  • Do all objects made of paper bend?
  • Do any of the objects made of wood bend? (balsa wood)
  • Did anything break when you tried to bend it? Why?
  • How is the wood that bends different from the wood that does not bend? (balsa is lighter
  • and thinner)
  • Which materials return to their original shape after you bend them?
  • Can you state a “rule” about bendability?

Concepts to be Assessed

(Unifying concepts (big ideas) and science concepts to be assessed using the Science Exemplars Rubric under the criterion: Science Concepts and Related Content.)

  • Physical Science — Properties of Matter: Students observe and compare physical properties of matter (comparing the weight, size and flexibility of solids) and classify materials according to properties.
  • Scientific Method: Students observe reactions of bending and not bending (cause and effect).
  • Mathematics: Students make precise measurements and collect, organize and analyze data appropriately.

Skills to be Developed

(Specific science process skills assessed using the Science Exemplars Rubric under the criteria: Scientific Procedures and Reasoning Strategies and Scientific Communication/Using Data.)

  • Scientific Method: Observing, predicting, recording and communicating.

Links to Science (and other) Standards

  • Scientific Method: Students describe, predict, investigate, and explain phenomena.
  • Scientific Theory: Students look for evidence that explains why things happen, and modify explanations when new observations are made.
  • Physical Science — Properties of Matter: Students describe and sort objects and materials according to observations of similarities and differences of physical properties (size, weight, color, shape, texture and flexibility).

Suggested Materials

Materials can be placed in plastic tubs from which cooperative groups of three or four students can freely select. I usually provide (for my first-grade learners) an independent science-center tub for further exploration during the week.

  • Tinkertoys
  • Cardboard
  • Wire
  • Paper clips
  • Tongue depressors
  • Coffee stirring sticks
  • Rubber bands
  • Paper
  • Foil
  • Cloth
  • Metal pipe
  • Balsa wood

Possible Solutions

The students’ solutions should demonstrate appropriate sorting of the solid materials under the “yes” column for those materials that bend and under the “no” column for those materials that do not bend. Students will discover through predicting and testing that some
materials will bend but return to their original shape, which caused some students to mark both the “yes” and “no” columns. After the completed investigation, the students discuss their observations and begin to draw conclusions based on their data.

Many of my students decided (concluded) that:

  • Materials that stayed bent were: pipe cleaners, wire, foil, paper and paper clips.
  • Materials that bent but did not hold their shape were: coffee stirrers, plastic straws, dishcloths, Styrofoam, rubber bands, balsa wood, paper towel tube pieces, Q-tips and ribbon.
  • Materials that did not bend were: Popsicle sticks, metal pipe, crayons, Unifix cubes, dominoes, wooden wheels, sea shells and old dry sponges.
Task Specific Rubric/Benchmark Descriptors
Click on a level for student example.
Novice This student did not understand or use the term, “bend” appropriately (all objects were recorded as “yes” after testing bendability); and did not connect the concept of bendability to testing the variety of solid materials. The student was unable to use prediction to come to consistent solutions (recording the word, “bends” for all predictions) which demonstrates limited or no use of scientific reasoning throughout the investigation.
Apprentice This student started to use a strategy of predicting and testing that was useful, but the recording is inconsistent and confusing. There is some evidence of scientific reasoning (predictions included both yes and no), but the concept of bendability is not completely understood (prediction does not always show understanding of each object’s properties). This student did not clearly represent many of the testing results.
Practitioner This student has a clear understanding of the concept of the bendability of solid materials. There is evidence of an effective strategy and scientific reasoning (completed the task and recorded all data) in this investigation. The representations are accurate and clear. This student also demonstrated to me how you could position your hands in such a way that the Popsicle stick could bend by twisting it. This is why s/he indicated a yes and no – because s/he could not maintain the bend.
Expert This student’s scientific representations demonstrate a deep understanding of the concept of bendability. This student used an effective strategy, and illustrated the ability to extend and generalize by searching around the room for new solid materials to test that were not in the tub. This student continued to make consistent and accurate predictions and tested and verified conclusions. The student indicated to me that if you were to put water on the old, dry sponge, then it would be bendable (cause and effect). The straw is recorded in the yes and no column because it depends on where you bend the plastic straw (in the middle or at the pleated sipping end).

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