Year+3+Science

Year 3 || =Light and shadows=
 * SCIENCE


 * Information ||

Objectives
• To know that light comes from a source and that objects can block light, causing shadows • To know that materials can be transparent, translucent or opaque • To know that the amount of light falling on a sensor can be measured, and that this can be used to investigate how opaque objects cause shadows • To consider that ‘ambient’ light explains why we do not get a zero reading

Prior learning
To benefit from this lesson, children should: • recognise that light is needed in order to see; • know that there are many light sources; • know that the main source of light in daytime is the Sun.

Vocabulary
transparent, translucent, opaque, shadow, block, direction, intensity

Resources
• data projector or interactive whiteboard linked to a laptop • light level sensor, datalogger and datalogging software (in this Example, //LogIT DataMeter 1000//) • range of materials – translucent, transparent, opaque (plastic bottles, colourless and coloured acetate sheets, fine net, thin nylon, greaseproof paper) • strong light source

ICT skills needed by teachers
To teach this unit, teachers need to know how to: • set up and use a datalogger with a light sensor; • use the supporting software.

Preparation for this lesson
Set up the datalogging equipment, sensor, associated software and strong light source. Ensure that the software scale responds appropriately as light levels change and that you have an appropriate range of transparent, translucent and opaque materials to hand.


 * Lesson extract ||

Starter
Explain to the children that they are going to undertake an investigation as part of their work on shadows. Show the children the equipment that you are going to use and explain how a light sensor can be used to measure light and therefore how much shadow a material casts. Q What the difference is between transparent, translucent and opaque? Q What is meant by different levels of light intensity? Show the datalogging screen and indicate how the different values being displayed can be interpreted in terms of how bright the light source is. Tell the children that the high value of the number (or the height of the bar) indicates that the light source being measured is very bright. Q What words could we use to describe the intensity of the light outside at the moment? Q How would the intensity change if we looked again this evening? Q What words could we use to describe the intensity of this light?

Main activity
Systematically test the materials by placing them in front of the light source and record the outcomes of the test. Start by showing the children the effect of placing an opaque material (a book) between the light source and the front of the light sensor. Q What has happened to the reading? (it has gone down but not to zero) Q Why do you think the values have changed? (because light cannot shine through the book because it is opaque) Take responses and confirm that the book is an opaque object and therefore is blocking most of the light. Q The value has decreased, but not to zero. Why do you think that is? (because of ambient light) Q What could we do to make the value go all the way down to zero? (block off all ambient light) Ask the children to make predictions about the readings that the other materials will give. Test these hypotheses and record what happens. Identify and discuss any results that the children were not expecting. Discuss with the children how to conduct their experiment; bring out that in order to make the test fair, the materials must be placed the same distance from the light sensor each time. Q What do you think will happen if we use a translucent material? Q What do you think will happen if we use a transparent material? Tell the children that we want to set up an investigation to find out which materials would make the best bedroom curtains. Q In terms of blocking out the light, what properties would we want the bedroom curtains to have? (a material that blocked out some but not all light)

Plenary
Consolidate what the children have learned about each material by asking them to describe the results of the test. Q Were the results what you expected? Q What did you learn about the different materials? Q What do the words translucent, opaque and transparent mean? Q What levels of light did each object let through? Q Did transparent materials let all the light through?


 * Notes ||

Links to QCA schemes of work
The lesson links to: QCA Science Unit 3F: Light and shadows QCA Science Unit 3C: Characteristics of materials QCA Science Unit 5E: Earth, Sun and Moon QCA Science Unit 6F: How we see things

Context of this lesson
This lesson contributes to section 9 of QCA Science Unit 3F: Light and shadows. Children should learn that opaque objects/materials do not let light through and transparent objects/materials let a lot of light through. They are expected to be able to use their knowledge about light and shadows to predict which materials will form a shadow, to plan how to test this and to draw conclusions from their results.

Subject links
This lesson can link to work in design and technology.

Why use ICT?
The advantages of using ICT are as follows. • Dataloggers give a high-quality time lapse record of a process, capturing scientific findings for closer, more effective study than real-time events. • As the datalogger is live, the physical circumstances can be changed, and these changes are immediately visible using the recording software. This provides excellent opportunities to set up hypotheses and make predictions, which can then be tested. • Data can be stored and compared with other situations using the graphing facilities.

SCIENCE Year 3 || =Teeth and eating=

Information ||

Objective
• To record the effect which some liquids have on our teeth and begin to use scientific knowledge and understanding to make explanations

Prior learning
To benefit from this lesson, children should: • know that what they eat is important for keeping healthy; • recognise a range of different foods.

Vocabulary
words related to scientific enquiry, e.g. observe, analyse, record; names of different teeth, e.g. incisor, molar, canine

Resources
• data projector or interactive whiteboard linked to a laptop • ICT suite or set of laptops • software which can display digital images and allows them to be captioned (in this Example, //Word//) • digital microscope and software (in this Example, //QX3(TM) Plus Computer Microscope//) • shallow dish (Petri dish) • collection of eggshells, or sterilised milk teeth (teeth from a local dentist) • selection of liquids, including cola

ICT skills needed by teachers
To teach this unit, teachers need to know how to: • link a digital microscope to the computer and save files; • import digital images into word processing software.

Preparation for this lesson
This lesson focuses on the fact that some foods and drinks can be damaging to our teeth and provides children with an experiment to illustrate this. Eggshells (or sterilised teeth) are placed in a number of dishes that contain different liquids. Photographs are taken and saved, over time, using a digital microscope. These images are then used as a basis for discussion evaluating the outcomes of the investigation.

Safety
Any real teeth must be sterilised before being taken to the classroom. It is possible to obtain ‘cleaned’ human teeth and/or plastic models of teeth from laboratory suppliers.

Lesson extract ||

Starter
Discuss with the children that they are going to undertake an investigation that explores the effect that some liquids have on our teeth. Discuss what it is like inside your mouth and ask the children how they might set up an experiment that simulates this. Ask them what liquids to use and explore what they think might happen. Discuss how long the process might take and agree timescales of when to take photographs of the tooth. Q What liquids shall we use? (cola, milk, water, orange juice) Q What do you think will happen if we put the teeth in each of these liquids? Q How long do you think the decay process might take? An hour, day, week, or month? Q Why might the use of the digital microscope be helpful?

Main activity
Place a tooth (or egg shells) in your chosen liquid and take a digital photograph of it at the start of the experiment and save this as an image. Project this image and ask the children to describe what they can see. Q What do you notice about the tooth? Q How is the microscope helping us with the observation process? Q How frequently should photographs be taken of each tooth? (this could be discussed with the children and might vary according to the liquid the tooth is in) Ask the children to record their observations at this stage. Once a number of images have been obtained over a period of time, show the children the range of images obtained for the teeth from being immersed in the different liquids. Q What do the photographs show us about what is happening to the tooth? Why do you think this is? Q What can we learn from this experiment about the care of our teeth?

Plenary
Ask the children what they have learned about the effect of different liquids on teeth. Ask them to explain why this might be and what preventative measures they might take to keep their own teeth healthy. Q Which liquids have affected the teeth and which have had no effect? Why do you think this is? Q How has the microscope helped compared with traditional methods? Q How might we look after our teeth?

Notes ||

Links to QCA schemes of work
The lesson links to: QCA Science Unit 3A: Teeth and eating QCA ICT Unit 3A: Combining text and graphics

Context of this lesson
Prior to this lesson children will have been learning about the importance of a varied diet to keep healthy and that we have different shapes of teeth for different purposes. Children will have made observations of teeth and understand that we have two sets of teeth and that adult teeth have to last.

Subject links
The lesson has potential links with work in design and technology and in geography.

Why use ICT?
The advantages of using ICT are as follows. • Using a digital microscope allows children to observe and analyse magnified images which can subsequently be used for analysis, presentation or publication. • ICT allows teachers to project enlarged visual images for whole-class demonstration and discussion.