(gentle music) <v ->In this year fall lesson,</v> from the unit, introduction to states of matter and changing states, pupils develop their substantive knowledge as they learn that temperature is the amount of heat in a material or object, and that it can be measured and compared. Prior to this, pupils have reflected on their own everyday experiences of using thermometers, such as checking body temperature when feeling unwell, and observing how some people use thermometers in their homes or gardens to measure the air temperature. In this lesson, pupils learn that scientists take accurate measurements, using a range of scientific equipment, including thermometers, to measure and compare temperatures. The teacher demonstrates how a thermometer works. As the temperature increases, the coloured liquid inside the thermometer expands, causing the top of the liquid to rise up the tube. Pupils also learn that the number on the scale next to the top of the coloured liquid represents the temperature, and that in the UK, degrees celsius is the standard unit of measurement for temperature. <v ->Many scientists use thermometers in their work</v> to measure and compare temperatures. Have you ever used a thermometer before? <v Student>Yeah. </v> <v ->Do we know how they work?</v> Prop a talk, go, how do they work? (students murmuring) The tube has got a scale on it, okay? <v ->It's got like celsius and degrees on the side of it. </v> <v ->If the end of the red line finishes,</v> it shows you how hot and cold it is. <v ->Oh my gosh, the number on the scale next</v> to the top coloured liquid is the temperature. So you are absolutely right. You are all absolutely right. The air is still touching the thermometer, so you can hold it up like this, and it'll still measure the temperature of the air. I've got my beaker of water on the table to keep it safe. I've placed my thermometer in the water. I'm holding onto the thermometer at the very, very top, and now, I'm gonna put my eye level level with the thermometer so I can get an accurate reading. And the temperature is 40 degrees celsius. <v ->This is like a thing that we use in science. </v> There's a coloured liquid inside, and it expands. <v ->If you are doing it with water, you hold the top of it,</v> make sure it doesn't detect your hands, and then you put it lightly in the water, make sure it doesn't touch the bottom or the sides. <v ->You have to hold it in the water for a little bit</v> because it might not perfectly measure it straight away. <v ->You look at the coloured line where it's gone up to it,</v> and then you have to keep your eye on it 'cause it might move anytime. And then you read the scale of how high it's going. <v ->Right now, it's 16 degrees celsius. </v> <v ->This video shows pupils as active participants,</v> using a thermometer to record the temperature of the air in the classroom, as well as the temperature of cold and warm water in separate beakers. Pupils work scientifically and with purpose as they learn to allow time for the coloured liquid to stop moving before they take their temperature reading. Keep their eyes level with the height of the liquid in the thermometer whilst taking the reading. Ensure the thermometer remains in the liquid, when measuring the temperature of the water. By doing so, they develop their disciplinary knowledge of how to take and record accurate measurements in standard units using a thermometer. Now that pupils have learned how to use a thermometer to take accurate temperature measurements, they should investigate how different materials change state when heated or cooled, and measure the temperature at which these changes occur in degrees celsius. (gentle music).