(upbeat music) <v ->In this year five lesson from the unit</v> "Forces, including Simple Machines," pupils continue to build their substantive knowledge of forces, focusing on air resistance as a type of frictional force that acts between the air and the surface of a moving object. Prior to this, pupils planned a fair test investigation to answer the inquiry question, does the area of a parachute canopy affect the time taken for the parachute to fall? To answer their inquiry question, pupils have made parachutes with three different sized canopies. They will drop each parachute from an agreed upon height, following relevant health and safety guidance, and then time how long it takes to hit the ground. <v ->Make sure someone's holding your hand,</v> step up and don't let go of their hand until they are secure on the chair. <v ->In this lesson, the teacher explains to pupils</v> that scientists often repeat the same test to gather a larger set of data. This helps them to ensure the results of the investigation are more reliable. It is important for pupils to understand that scientists do not take repeat measurements to make their tests fair. <v ->Well, scientists often repeat the same tests</v> to gather a larger set of data. This helps them to make sure that the results of their investigation are more reliable. So that's what we are gonna do today. <v ->The video shows pupils as active participants,</v> working scientifically and purposefully by safely carrying out their fair test investigations. They will take repeat measurements by dropping each parachute three times and recording multiple sets of data. There are opportunities for teachers to reinforce meaningful links between mathematics and science in this lesson. Pupils revisit the procedural knowledge required to use a stopwatch to record times in a systematic way. They also practise their mathematical skills by rounding the measurements of time. <v ->I want you to write down the time</v> to the newest two decimal places, which means you might even need to round up or round it down. One to four, hit the floor. Five to nine, climb the line, well done. So you're gonna need to round it. So you should end up with three different results. <v ->By carrying out their parachute investigations,</v> pupils develop their disciplinary knowledge of how to take measurements with a stopwatch with increasing accuracy and precision, as well as how to take repeat readings when appropriate. Now that pupils have carried out their fair test investigations and know how to control variables and take repeat measurements, it is important that they review their investigations by checking whether the data they have collected appears reliable. They should have opportunities to make sense of their findings and answer the original inquiry question in the form of a conclusion. (upbeat music).