6 L.O.2To be able to use, read and write standard metric units of length including their abbreviations and relationships between them.To be able to convert larger to smaller units of lengthTo know imperial units (mile)
7 Q. Tell me the name of a measurement of length.Q. Which of these units is the longest?
21 Use your sheet OHT 9. 3 to answer these Use your sheet OHT 9.3 to answer these. Record the answers in your book.1.Which measurement is nearest to the width of yourfingernail?2. Which is nearest the length of the classroom?3. Think of things which approximate to other measurements shown and record them.Prisms – 8 measurementsSpheres – 6 measurementsTetrahedra – 5 measurementsRecord your measurements in other units as well.
22 L.O.2To be able to estimate / measure anddraw lines to the nearest mm.
23 You will need a ruler which measures in mm. Work with a partner. One of you draw a line 15cm. long - the other will check.Now the other will draw a line 150mm. long which the first will check.Q. Why is it important to start measuring fromzero on the ruler and not from the end of theruler?
31 L.O.1 To be able to double or halve any whole number to 100
32 We are going to halve numbers then double them. REMEMBER !When we double we x 2;when we halve we /2
33 L.O.2To understand, measure and calculate the perimeter of polygons.To be able to express the formula for the perimeter of a rectangle as “twice length, twice breadth”.
34 Q. How would we calculate this distance? Q. What is the correct mathematical term for finding the distance around the outside edge of a 2-D shape?Q. How would we calculate this distance?Take and discuss answers.
36 Q .How can we calculate the perimeter of this shape? Q. When we calculate the perimeter of a rectangle do we need to measure all the sides?
37 We can use the formulatwice the length plus twice the breadthThis is often written as(2 x L) + (2 x B)
38 In your book draw a rectangle which has two sides of 8cm. and two of 5cm.Find the perimeter of your rectangle by using the measurements of only TWO sides.Complete this equation by filling in the numbers:P = ( 2 x ) + ( 2 x )== cm.
39 Q . Can you think of any shapes where you would not need to measure every side to calculate the perimeter.Answers please!
40 A regular hexagon would be six times the length of one side - its formula is x L
41 LOOK at Activity Sheet 9.2Decide which shapes would need every side measuring and which ones could have short cuts.Write the letter for each shape in your book and next to it express the perimeter of that shape in words and in letters where appropriate.e.g. Perimeter Shape A : Measure every sideB : Short cut
42 REMEMBERWhen calculating the perimeter of a rectangle we do not have to measure all four sides, only two. We can then use the formulaP = (2 x L) + (2 x B)or, if we use lower case letters….p = (2 x l) + (2 x b)
43 Calculate the perimeters of shapes D, E, G and J. Convert your answers to millimetres.In each case write down the number of sides you measured and show how you worked out the perimeter.
44 By the end of the lesson children should be able to: Express the formula and calculate the perimeter of a rectangle.
48 Take turns with a partner to roll two 0 – 9 dice. FOUR IN A ROWUse Resource Sheet 9.2Take turns with a partner to roll two 0 – 9 dice.Any of the four number operations may be applied to the numbers you roll e.g. if you roll a 6 and a 7 you could place counters on squares 42 ( 6 x 7 ), 13 ( ) and 1 (7 – 6 ).The first person to get four in a row wins.
49 L.O.2To understand, measure and calculate the perimeter of rectangles and regular polygons.To be able to measure lines to the nearest millimetre.To be able to use, read and write standard metric units of length, including their abbreviations and relationships.
50 PROBLEMA farmer is fencing off sections of land using straight edges. For each section the farmer uses 30 m. of wire. What different shapes could each of the sections be?Show at least 5 different shapes. In each case show how you used the 30 m. of wiring.10 minutesI will ask you for your answers later!
51 What kind of triangle is this and what is special about it?
52 What kind of triangle is this and what is special about it? If the length of one side is 80 mm. what is the perimeter of this equilateral triangle in mm., in cm.? Discuss in pairs.
53 One way to work out the answer is to use the formula : P = 3 x LQ. If a regular pentagon has a side of8 cm. what would its perimeter be?
54 Q. Where in real life do you think you would need to calculate the perimeter of something? Q. If a rectangle has a perimeter of 20 cm. what could be the lengths of its sides?Q. If a regular hexagon has a perimeter of 75cm. What would the length of one side be?
55 Prisms – 8 problems per pair. Spheres – 6 problems per pair Noe its your turn to invent some perimeter problems. Work with a partner but both of you write down all the problems you create. Try them on other people on your table.Prisms – 8 problems per pair.Spheres – 6 problems per pairTetrahedra – 4 p. p. p.8 minutes
56 By the end of the lesson the children should be able to: Work out and express in words a formula for finding the perimeter of a regular polygon.Measure perimeters to the nearest millimetre.
58 To be able to convert larger to smaller units of measure L.O.1To be able to convert larger to smaller units of measure(e.g. km. to m. and l. to ml. )
59 We are going to play the follow-on game. ……. quickly!
60 L.O.2To be able to use knowledge of perimeter and area to solve a given problem – and explain methods and reasoning.
61 This square has a side of 20cm. Q. What is the perimeter of this square?Q. What is the area of this square?
62 If the side of a square is 20cm. : Its perimeter is 80cm.( 20cm. + 20cm.+ 20cm. + 20cm)Its area is 400 square cm.(20cm. x 20cm.)
63 I have folded the square in half. 20cm.10cm.Q. What is the area of the rectangle?Q. What is the perimeter of the rectangle?
64 For the rectangle which has sides 20cm. and 10cm. : The area is L x B = 20cm. x 10cm.= 200 square cm.The perimeter is 2 ( L + B )= 2 ( 20cm cm.)= 2 (30cm. )= 60cm.
65 I have folded the rectangle in half. 10cm.10cm.Q. What is the name and area of the shape now?Q. What is the perimeter of the shape?
66 The shape is now a square. 10cm.10cm.Its area is 10 cm. x 10 cm. = 100 square cm.Its perimeter is 10cm. + 10cm. + 10cm. +10cm.=40cm.
67 Q. What has happened to the area of the original square? 10cm.20cm.Q. What has happened to the area of the original square?Q. What’s happened to the perimeter of the original square ?
68 Q. What’s happened to the area / perimeter of the original square?
69 PARALLEL to the edges of the original shape. Keep cutting out parts of the original square.You must keep the cutsPARALLELto the edges of the original shape.What is happening to the area / perimeter of the square?
70 You should find that :the perimeter stays the samebutthe area reduces.
71 I am using a line 60 cm. long to make another square – Whoopee! Q What is the perimeter / area of the square?
72 Using the same length of line I have made a rectangle. Q. What is its area / perimeter?10cm.20cm.
73 Yet another rectangle using the same length of line. Q. What is its area / perimeter?12cm.18cm.
74 INVESTIGATIONSHow many different rectangles can you draw which have a perimeter of :30cm. – prisms24cm. – spheres20cm. – tetrahedraWhat is the biggest area you can make?10 minutes !
75 Q. Did anyone use a system as they were working? One way of working is to increase the length and at the same time reduce the breadth like this :PerimeterLengthBreadth24 cm.11 cm.1 cm.10 cm.2 cm.9 cm.3 cm.
76 We can extend this table: Perimeter Length Breadth Area 24 cm. 11 cm. 11 sq.cm.10 cm.2 cm.20 sq.cm.9 cm.3 cm.27 sq.cm.8 cm.4 cm.32 sq.cm.Q. What is the biggest area which can be made using a shape which has straight sides and a perimeter of 24cm.
77 The largest possible area for a shape with straight sides and a perimeter of 24 cm. is 36 square cm.
78 By the end of the lesson children should be able to: Use their knowledge of perimeter to solve a problem.Explain their methods and reasoning.Realise the benefits of a systematic approach when solving problems.