Measures 3 Area, volume & perimeter Objectives Find the area of rectangles and compound rectilinear shapes Find the perimeter of rectangles and compound rectilinear shapes Find the volume of cuboids For this unit you will need: 0 to 9 dice, Perimeter and area at http://www.bgfl.org/bgfl/custom/resources_ftp/client_ftp/ks2/maths/peri meter_and_area/index.html, 3D boxes at http://www.interactivestuff.org/sums4fun/3dboxes.html Watch out for pupils who: confuse area and perimeter; do not know the appropriate units for perimeter, area and volume; do not use the properties of rectangles to work out the lengths of missing sides in rectangles or compound shapes. HSNP © Hamilton 2014 Stepping Up Term 3 Measures 3 Session 1 Objective: Find the area of rectangles and compound rectilinear shapes Teacher input with whole class Sketch a rectangle on the board and label two sides 5cm and 8cm. Remind pupils how they can find the area by multiplying the two sides together and that the area will be in square cm. Draw the same rectangle on a squared background so pupils can see the 40 squares arranged in 5 rows of 8. Paired pupil work Pupils roll a 0 to 9 dice twice to generate two lengths of a rectangle. They roll again if they roll 0. They sketch it and find the area. Repeat at least five times. How many can they find in two minutes? Teacher input with whole class Use Perimeter and area at http://www.bgfl.org/bgfl/custom/resources_ftp/client_ftp/ks2/maths /perimeter_and_area/index.html, click on area, the rectangle, next, level 2 and then on the shape and discuss the animation. Click ‘next’. Pupils work in pairs to find the area of the shape on the screen. Take feedback, and enter the most common answer, then click ‘check. Repeat. Click ‘level menu’ and repeat with level 3. HSNP © Hamilton 2014 Stepping Up Term 3 Measures 3 Session 2 Objective: Find the perimeter of rectangles and compound rectilinear shapes Teacher input with whole class Sketch a rectangle on the board and label two sides 5cm and 6cm. How can we find the perimeter, the distance round the edge? Discuss how we can add 5, 6, 5 and 6 but also remind pupils how they can find the perimeter by doubling each side and adding, or adding then doubling. Pupils find the length in cm. Paired pupil work Pupils roll a 0 to 9 dice twice to generate two lengths of a rectangle. They roll again if they roll 0. They sketch it and find the perimeter. How many can they find in two minutes? Teacher input with whole class Draw a compound shape made from two rectangles with not all sides labelled. Discuss how pupils can find the perimeter, deriving the lengths of unlabelled sides. They put two of their own rectangles together and find the perimeter of the new shape. Sketch a regular hexagon and label one side 12 cm. How can we find the perimeter of this shape? What if it were an irregular hexagon? What if this shape was a regular pentagon? Octagon? A regular shape has a perimeter of 72cm.If the shape is a hexagon, what is the length of each side? What if the shape is an octagon? Paired pupil work Pupils roll a 0 to 9 dice twice to generate the number and length of sides of a regular shape. They roll again if they roll 0, 1 or 2. They sketch the shape and find its perimeter. How many can they find in two minutes? Teacher input with whole class Write the following units on the board and ask pupils which can be used to measure perimeter: cm, m2, km3, mm2, cm3, m, km2, cm2 Which can be used for area? HSNP © Hamilton 2014 Stepping Up Term 3 Measures 3 Session 3 Objective: Find the volume of cuboids Teacher input with whole class Use 3D boxes at http://www.interactivestuff.org/sums4fun/3dboxes.html and ask pupils to discuss in pairs how many cubes are in the shape. Repeat several times. Ask pupils to explain to a partner how they can find the volume of a cuboid. Take feedback. Agree that they can multiply the length and breadth of the base to find the number of cubes in the base layer, then multiply by the height to find the number of cubes in the whole cuboid. Ask pupils to work in pairs to list the units which can be used to measure volume (e.g. mm3, cm3, m3, km3). Take feedback and make a class list. Paired pupil work Ask pupils to sketch four different cuboids and to label three different dimensions. They find the volume of each and check with partner. They then work in pairs to investigate which cuboids could have a volume of 24cm3. Teacher input with whole class Take feedback, and list solutions together as a class. HSNP © Hamilton 2014 Stepping Up Term 3