Grade 5 Science
Optional Unit: Machines and Work

Unit Overview:

The principles behind simple machines are studied with reference to the use of those machines in transferring forces and accomplishing work.

Related units:

This unit is not related to any other unit in grade 5. The Optional Unit on Simple Machines in grade 3 is related.

Suggested themes:

force, machines, technology

Factors of scientific literacy that should be emphasized.

Common Essential Learnings foundational objectives which should be emphasized:

To strengthen students' knowledge and understanding of how to compute, measure, estimate and interpret numerical data, when to apply these skills and techniques, and why these apply to the study of machines. (NUM)

To develop a contemporary view of technology. (TL)

Science foundational and learning objectives:

Explain the principles of simple machines.
1. Demonstrate how the three classes of levers work.
2. Demonstrate how to use pulleys to lift a mass.
3. Compare force required to lift objects directly and with simple machines.
4. Identify some common applications of simple machines.
5. Distinguish between simple and compound machines.
work done in moving objects.
1. Use a spring scale to measure force.
2. Define work.
3. Calculate the work done on an object.

Suggested Activities:

As a class or in small groups, take a walk around the school to find evidence of the kinds of machines that are used. Classify the machines as simple or compound machines. Try to identify which of the simple machines may be used in a more complex machine. This could serve as a springboard for starting this unit. Later as an independent project, machines used at home might be identified. These could be reported in a choice of forms: graphs, lists, written report, pictures, or a combination of formats. A further extension of this could be interviewing school or community personnel to find out about simple machines used in their work.

Factors: A4, A5, B3, B13, C1, C2, C5, C7, C8, C9, C12, D1, F3, F5, G1
Objectives: 1.4
Assessment Techniques: 1, 3, 6

Common Essential Learnings: Communication, Critical and Creative Thinking, Independent Learning. Students make connections between the environment and their learning.
Another springboard for starting this unit, would be to web the students' present knowledge either in small groups or as a whole class. Students might also have suggestions for some activities they would like to be involved in and ideas about how they might be evaluated. If students have not experienced the Optional Unit: Simple Machines in grade three, basic information on the lever, screw, pulley, wedge and inclined plane, and the wheel and axle may need to be explored along with gravity, friction, energy and force. Refer to the activities included in that section.

Factors: A2, A5, B3, B7, B9, B13, B17, C2, C4, C5, C8, C9, D1, E3, F2, F5, G1, G3
Objectives: 1.3, 1.5, 2.1
Assessment Techniques: 1, 3, 6

Common Essential Learnings: Communication, Critical and Creative Thinking, Independent Learning. Students are provided with the opportunity to plan for their learning and to have hands-on experiences.
This unit lends itself to theming, particularly involving the use of a Medieval castle setting where students might link literature and history to their science. Construction of a "setting" which could include moat and drawbridge, ramps, battering rams, etc. would involve application of simple and compound machines. Students could research the defence of a castle and build structures involving as many "Simple and Compound Machines" as possible. This could be an independent, small group, or class project. Have students include some written reflections, observations, or statements about the applications of simple machines in the project.
Factors: A2, A4, B1, B3, B7, B9, B15, C4, C8, C9, D1, F3, F5, G1
Objectives: 1.4, 1.5
Assessment Techniques: 1, 3, 4, 9

Common Essential Learnings: Communication, Critical and Creative Thinking, Personal and Social Values and Skills, Technological Literacy, Independent Learning. Students have an opportunity to research, plan, and apply their knowledge as one aspect of their learning.
On the playground, use the teeter totter to experiment with balancing the use of mass and force required as this lever is raised and lowered. This is a first class lever.
1. Use of balances and scales in the classroom can be set up as centre activities in science or in mathematics to further demonstrate use of first class levers. (If the force arm is longer than the weight arm from the fulcrum, less force is needed. If the force arm is shorter than the weight arm, more force is required.)
2. Use a metre stick, a spring scale, and some weights which can be suspended from the metre stick to experiment with second class levers. Hold or tape a meter stick to a table so that it is suspended beyond the edge. Place an elastic around the metre stick near the overhanging end onto which the spring balance can be attached. The fulcrum will be the table edge. Suspend the weight at various points along the metre stick and compare readings of the spring scale. Record in chart form. Does a pattern develop as the weight is moved along to different positions on the metre stick? Repeat but shorten the distance between the fulcrum (table edge) and where the spring balance is attached. Keep the weight between the two positions. Are the results still similar? Discuss. Record. [When the force arm is longer than the weight arm (distance from the fulcrum) less force is required but the distance raised is greater.]
3. A third class lever has a fulcrum at one end, the weight at the other and the spring scale to measure force between the two. Place the end of the metre stick against an upright surface such as the wall. You may need a partner to gently hold the fulcrum end in position. The weight to be lifted should be fastened at the opposite end. Try placing the spring scale at various positions along the metre stick as you raise the weight 30 cm or some other desired height. To mark the height the weight is to be raised, use a box or pile of books. This will provide consistency in the height raised each time. What does the spring scale read when it is close to the weight? ... farther away? Approximately how far did you need to move the spring scale upward each time? Discuss and record results. (The force required to lift the weight is greater than the weight. It increases as the force is further from the weight, but the distance raised is less.)
4. As a group, generate examples of each class of lever. Which is most often used? First class--pump handles, crowbar, teeter totter, some salad tongs, scissors, pliers, shears, hammer, etc. Second class--paper cutter, nutcracker, wheelbarrow, etc. Third class--candy tongs, fishing pole, tweezers, stapler, shovel, etc. Record examples of the different classes of simple machines. Record how each class of lever works.
Factors:
A2, A4, A5, B1, B3, B7, B9, B10, B13, C1, C2, C4, C5, C8, C9, C10, C12, D1, E3, E6, F3, F5, G1
Objectives: 1.1
Assessment Techniques: 1, 3, 5, 9

Common Essential Learnings: Communication, Critical and Creative Thinking, Independent Learning. Students have active involvement in activities to promote learning and make connections to real world examples of machines.
Using of recycled or "found" materials (toilet paper rolls, tubes, straws, lids, boxes, pieces of wood, etc.) to construct simple machines provides hands-on participation. These activities may be arranged as in-class centres, as a whole class project, or as a parent and child evening with tasks to be done at each centre.
1. Wheel and axles
  With straws as axles and heavy cardboard wheels, cars can be constructed from toilet paper tubes. Use of a hole punch to create holes for the axles and a cut-out on top allows the student to put in a driver or carry a load such as an egg. A dab of the hot glue gun where the wheels are slipped onto the straws allows axles to turn without the wheels falling off. (See grade 3 optional unit.) Races down ramps are possible. Measuring distances cars go adds another dimension. Cars can be "souped-up" with colour, flags, headlights, and tailpipes. Another version of the wheel and axle is in the use of pinwheels and waterwheels. Pinwheels may be made from a square of paper. Use a ruler to draw on the diagonals to find the centre. Cut along the lines about two-thirds of the way towards centre. Bend in but do not crease every second point. Put a straight pin through the ends and the centre point of the pinwheel. Secure to a straw. Blow on the pinwheel to observe it turning. Poke a hole through the centre of an aluminum pie plate and place a pencil through the hole. Around the edge at regular intervals make cuts with scissors (about eight). Give each edge segment a bend and twist to form the blades of the water wheel. Pour water to make the blades turn or hold the water wheel under a slow-running tap to see it in action. If possible look inside an old clock or watch. Notice the gears (wheels and axles). Gears can be made with lids and coarse corrugated cardboard strips glued around the outer edges. Find the centre of each lid. Nail these "gears" to a piece of wood through the centre of each lid so that one gear meshes with the next. Try this with the same sized gears and different sized gears. Turn one. What happens to the other? Record observations.
2. Screws
  Have students examine various screws to observe the pitch of the threads. Discuss which would go into wood or metal faster with a single turn of the screw head. Why are threads on low-pitched screws closer together? Have students use a right-triangular piece of paper to demonstrate the screw. Along the diagonal put a dark line. Carefully roll the triangular paper around a pencil starting at the shortest edge and rolling to the point. What do you observe? Make a hole in a thick piece of cardboard just large enough for the end of a bolt. Screw the bolt onto the cardboard a few turns so that its end shows. Put on the nut. Screw the nut on further. What happens to the cardboard? Discuss.
3. Inclined planes
  Have students construct inclines using halves of tubes supported so that marbles, small cars, or other objects might roll down the ramp. Again distances can be measured when varying degrees of incline are used. The use of a spring scale can also be included as students measure the amount of force needed to pull objects up different inclines.
4. Pulleys
  If possible, obtain pulleys that may be used as fixed or movable pulleys. Examples: clothesline pulleys, meccano, spools secured by nails or wires. Fasten a pulley to a piece of wood that can be placed at least a metre from the floor. Use a spring balance, a string, and a known weight to measure the force required to lift the weight. What do you find? (The single-fixed pulley does not change the force required but does change the direction the weight goes up as force is applied downward. A flag pole is a good example to look at.) Fasten the end of the string to the wood. Use a single movable pulley to which you can fasten the weight. Pull upward with the spring balance attached to the other end of your string. What do you discover? (As in the first activity with the fixed pulley, direction is changed. This is how a roofer might lift shingles up to where the work is being done.) Use both the single- fixed and movable pulley with the weight attached and a longer string fastened to the wood. Have the string go through the movable pulley and then the fixed pulley before attaching the spring scale. Now pull down. What do you find when two pulleys are used? (The force should be about half the weight being raised.)
5. Levers (See Activity #4 above.)
  Use your mathematics skills to measure the distances that "simulated" forces and weights move using different classes of levers. You will need two pieces of light weight cardboard perhaps 40 cm X 2 cm. Hole punch near both ends and at several points near a midpoint on each. Use a paper fastener as a fulcrum to secure the two pieces of cardboard together. On a large piece of newsprint draw a baseline. Lay your lever along this line. Fasten the bottom one with two short pieces of tape. For a first class lever, the fastener should be at midpoint. Rotate the top lever. Measure from your baseline to the hole punched at each end. One will give you the distance the "weight" was lifted, while the second will measure the distance the "force" moved downward. Change the fastener (fulcrum) to another point off centre. Again rotate the lever and make measurements. Make a chart of your results. For a second class and third class lever, the fulcrum will move to an end hole. Again fasten down the bottom lever to your base line. As you rotate the lever (for second class levers) your force distance will be the measurement at the end opposite the fulcrum while the weight distance will be at various points nearer the middle of the lever. For the third class lever force and weight change positions. Make several measurements for each class of lever. Record and discuss.
6. Wedges
  With supervision, have students use the paper cutter, scissors, and various types of knives (perhaps to cut fruit for a fruit salad). This integrates well into a Nutrition theme. Allow students to examine the cutting surface of axes, saws and chisels. Have them notice not only the cutting edge but the wider part which helps separate the wood. If there is sufficient supervision and safety is stressed students may be able to use these tools. Another type of wedge has a rounded point like the nose cone of a rocket or blunt punches. A third type of wedge has a pointed end such as a needle, pin, or nail. Have students record examples of wedges and how they work. Students might use a long narrow rectangular piece of paper, draw one diagonal, and cut along the diagonal. What do you now have? (two inclined planes or right triangles) Often door wedges and chisels are shaped like this. Now flip one triangle and place the long sides together so that the points are together with short sides of the original rectangle meeting at the 90 degree corners. Diagonals will become the opposite sides of the isosceles triangle. Tape the adjoining edges. Now you have a wedge like that found in a knife or an axe.
Factors:
A4, A5, B3, B7, B10, B13, B15, C1, C2, C4, C5, C7, C8, C9, C10, C12, D1, E3, F3, F5, G1
Objectives: 1.1, 1.2, 1.3, 1.4, 1.5, 2.1, 2.2
Assessment Techniques: 1, 3, 4

Common Essential Learnings: Communication, Critical and Creative Thinking, Numeracy, Personal and Social Values and Skills, Technological Literacy, Independent Learning. Students have their learning enhanced when they are able to manipulate objects.
Have students design or "invent" a machine:
1. to help them do some work;
2. to help them exercise their pet; or,
3. to aid in movement from one place to another.
Students should be prepared to explain how their construction works, what task it does, what force might need to be applied, and where it would be most useful. Students may use recycled materials collected by the class, materials brought from home, or use shared items. Encourage independent and cooperative work. Some students may choose to do independent work at home and share their creation with the class later.
Factors: A2, B1, B3, B7, B9, B13, B17, C2, C5, C8, C9, D1, E3, F2, F5, G1, G3
Objectives: 1.5, 2.4
Assessment Techniques: 1, 3, 4, 5, 9

Common Essential Learnings: Communication, Critical and Creative Thinking, Personal and Social Values and Skills, Technological Literacy, Independent Learning. Students have the opportunity to be creative as they construct simple or compound machines that do "work".
Students might construct paper boats by paper folding, and experiment with ways to move them across a water surface (air pumps, blowing, paper clips and magnets, etc.) Vary the size or material from which the boat is made. Which method of movement is most efficient? What methods will work with a dinky car to move it across a flat surface? Make measurements and record. Encourage paired and small group work. Have students discuss and share results.

Factors: A4, A5, B3, B7, B10, B13, B15, C1, C2, C4, C5, C7, C8, C9, C10, C12, D1, E3, F3, F5, G1
Objectives: 2.2, 2.4
Assessment Techniques: 1, 3, 4

Common Essential Learnings: Communication, Critical and Creative Thinking, Numeracy, Personal and Social Values and Skills, Independent Learning. Students have input into their learning, while being encouraged to use their creativity.
Work is done when movement occurs as a result of application of a force. Force X the distance moved equals the work done. Demonstrate this by sliding a known weight one metre. Use a spring scale to measure the force used to move the weight. Half the weight but move it two metres. Again measure with the spring scale. Do you do the same amount of work in each case? Use a balance with weights. (Check with primary math classrooms for balances onto which plastic or metal weights may be attached.) Place one weight at the ten. On the opposite side place two weights at the five. Again we have used distance and force (weights) to do equal amounts of work. Provide students with the opportunity to explore other variations with balances, teeter totters, or their own constructions. Have children record what they did and their findings. Share.

Factors: A4, A5, B3, B7, B10, B13, B15, C1, C2, C4, C5, C7, C8, C9, C10, C12, D1, E3, F3, F5, G1
Objectives: 2.1, 2.2, 2.3, 2.4
Assessment Techniques: 1, 3, 4, 6

Common Essential Learnings: All the CELS ( Communication, Critical and Creative Thinking, Numeracy, Technological Literacy, Personal and Social Values and Skills, Independent Learning) can be incorporated here.
Often cube-a-links and other building toys (meccano) can be used by students to demonstrate how a simple machine works. Popsicle sticks, bits of wood, hammers and nails, etc. may be left at a centre for students to work with during free time. Allow for individual projects that might demonstrate creativity. Can inclined planes, pulley systems, levers, etc. be created in a number of different ways? How do they help do work? Have students write about their projects. Take time to share with the class.

Factors: A4, A5, B3, B7, B10, B13, B15, C1, C2, C4, C5, C7, C8, C9, C10, C12, D1, E3, F3, F5, G1
Objectives: 2.3
Assessment Techniques: 1, 3, 4, 5, 6, 9

Common Essential Learnings: Use Communication, Critical and Creative Thinking, and Independent Learning.
Work and energy are measured in the same units. Energy is measured in joules or Newton-metres. Power is a measure of how quickly work is done. Electrical power or energy used is measured in kilowatt-hours. Use of electrical energy is just one way we do work in our homes. Have students record the number on the power meter at home. Record it again one week later. Compare results. How much power was used? Have each student ask their families to make an effort to conserve energy for a week. Record results once again. Was there a difference? What other factors may have played a part in the results? (kind of weather over the two week period, number in the family and their ages, activities of the family, number of vehicles using plug-ins, etc.) In what ways can energy be conserved? Discuss.

Factors: A4, A5, B3, B7, B10, B13, B15, C1, C2, C4, C5, C7, C8, C9, C10, C12, D1, E3, F3, F5, G1
Objectives: 1.3, 1.4
Assessment Techniques: 1, 3, 4, 9

Common Essential Learnings: Communication, Critical and Creative Thinking, Numeracy, Technological Literacy, Independent Learning. Students have the opportunity to do some independent research.
Have students work with the vocabulary terms used in this unit on Machines and Work. Have students generate a list of words which may be used as they construct puzzles, crosswords, word searches, riddles, or games. Students may choose to make a dice game in which question/answer cards are necessary if certain spots are landed upon. They may choose to develop questions and answers or definitions and answers to make a variation of Trivial Pursuit. This could be an independent or small group task or assignment. An alternate strategy to reinforce vocabulary and concepts from this unit, would be for pairs of students (or individuals) to develop a set of 20 fill in blank statements, matching, or one or two word answer questions. Pairs could then exchange sheets and try the task. This provides for review as tasks are designed and a further check as another's tasks are completed using open book or a "test". If there is much variation in level of difficulty of designed tasks, one or two tasks could be duplicated as an assessment tool.

Factors: A4, A5, B3, B7, B10, B13, B15, C1, C2, C4, C5, C7, C8, C9, C10, C12, D1, E3, F3, F5, G1
Objectives: 1.5
Assessment Techniques: 1, 3

Common Essential Learnings: Communication, Critical and Creative Thinking, Independent Learning. Students have input into planning for their assessment.
Research can be a component of this unit. Have students discuss the connection between work and energy (Activity #8 and #10). Energy is the ability to do work. Together generate a list of the kinds of energy we use as we do work, how we can conserve that energy, the sources (resources) for our energy and the kinds of energy most commonly used in Saskatchewan. Other aspects of this unit might be highlighted such as simple and compound machines from both a present and historic viewpoint. After some ideas have been listed or webbed, have students identify ways to obtain research information (interviews, guest speakers, print and audiovisual materials, etc.) and ways to report it (written, graphs and tables, charts, samples and displays, oral presentations, audiovisuals, etc). Tasks may be undertaken individually or in small groups. Allow students to have input into assessment of their projects.
Factors: A4, A5, B3, B7, B10, B13, B15, C1, C2, C4, C5, C7, C8, C9, C10, C12, D1, E3, F3, F5, G1
Objectives: 1.4, 1.5, 2.3, 2.4
Assessment Techniques: 1, 3, 4, 6, 9

Common Essential Learnings: Communication, Critical and Creative Thinking, Numeracy, Personal and Social Values and Skills, Independent Learning. Students have input into planning for their learning. Freedom to investigate any one of a variety of topics in individual ways provides an opportunity for exploration using the media of choice.
If possible, arrange a field trip to an industry where students may observe first-hand the use of simple and compound machines as they help do work. This could be a garage, farm workshop, manufacturing industry, power station, etc. Have students record the kinds of tools and machines used and how they help perform work. Student might provide a written report of their learning following the trip.

Factors: A4, A5, B3, B7, B10, B13, B15, C1, C2, C4, C5, C7, C8, C9, C10, C12, D1, E3, F3, F5, G1
Objectives: 1.4, 1.5, 2.3
Assessment Techniques: 1, 3, 5, 9

Common Essential Learnings: Communication, Critical and Creative Thinking, Numeracy, Personal and Social Values and Skills, Independent Learning. Students have the opportunity to learn beyond the classroom.

Grade 5 Science Optional Unit: Machines and Work