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missburkerocks.wordpress.com
Length A length is a distance. In Australia we use the metric system for
measurement and the base unit is the metre. The length of an object is commonly
measured in: millimetres (mm) centimetres (cm) metres (m) kilometres (km).
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1km = 1000m (km m = x1000) 1m = 100cm (m cm = x100) 1cm = 10mm (cm mm = x10)From this information you can create a
Length conversion chart:
km 1000
1000m
100 100
cm10 10
mm
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Length Conversions1. Write the question.2. Use the conversion chart to identify
conversion factor.3. Multiply or divide original
measurement.4. Put correct units.
Eg/ Complete the following metric conversions.a)756m=__________ kmb)0.034km (m)c)374cm=_________md)54cm (mm)e)380mm (cm)f)374cm (km)
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ClassworkYear 7Text: Cambridge Essential Maths 7: Chapter 11Ex 11B Q4a-f, 5a-c, 6g-h, 7a-f, 10a, b, 12, 13, 17, 19
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Length Conversion: Exit questions
Complete the following metric conversions.
a)38m=__________ kmb)24cm=_________mmc)49cm (m)d)380m (mm)
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Geometric symbols A box in the corner of
an angle denotes a right angle
Similarly marked segments are congruent (the same length)
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Perimeter Perimeter is the measurement of the
distance (length) around the outside of a 2D shape.
To calculate the perimeter of an object we add the length of all of the sides together once they are in common units.
8cm
5cm
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Calculating Perimeter1. Convert all dimensions (measurements) to the same
units (mm, cm, m, km).2. Calculate and record any missing lengths.3. Add all lengths together.4. Put correct units.
Examples:
8cm
5cm
1.
2.
3.
4cm
9cm
8mm
9mm
4.
98cm5m
4m
10m
4m
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ClassworkYear 8Text: Cambridge Essential Maths 8: Chapter 4 Ex 4A Q3, 5a,b,e,f,I,j,m,n, 6, 7c-f, 8a-d, 10Remember to show all working
Year 7Text: Cambridge Essential Maths 7: Chapter 11Ex 11C Q1, 3, 4, 5, 6, 8, 11Remember to show all working
missburkerocks.wordpress.comArea
1km2=1 000 000m2 (km2 m2= x10002) 1m2=10 000cm2 (m2 cm2= x1002) 1cm2=100mm2 (cm2 mm2= x102)
if 1cm = 10mm then 1cm x 1cm = 10mmx10mm
=102 mm2
=100mm2
1cm
10mm
Area is the amount of space inside a 2D shape. The area is measured in squared units (mm2, cm2, m2 or
km2). Units are squared units as you are calculating how many
1x1 squares would fit inside the shape!
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ClassworkYear 8Text: Cambridge Essential Maths 8: Chapter 4 Ex 4C 5a-fEx 4D 3a,b,d,e,g,h,j,kRemember to show all workingExtensionEx 4C 1a,b, 2, 6Ex 4D 6, 7, 8
Year 7Text: Cambridge Essential Maths 7: Chapter 11Ex 11D 6a-fEx 11E 4a-eEx 11F 3a-dRemember to show all workingExtensionEx 11D 7, 10, 12Ex 11E 3, 6, 10, 11Ex 11F 6, 8
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Write the formulae for the following shapesa) b)
c) d)
e) f)
Area: Year 7 exit questions
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Area Conversions
1km2=1 000 000m2 (km2 m2= x10002) 1m2=10 000cm2 (m2 cm2= x1002) 1cm2=100mm2 (cm2 mm2= x102)
if 1cm = 10mm then 1cm x 1cm = 10mmx10mm
=102 mm2
=100mm2
1cm
10mm
Remember: Area is the amount of space inside a 2D object. Units are squared units as you are calculating how many 1x1 squares would fit inside the shape!
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Area continued From this you can create an area
conversion chart:km2
10002 10002
m2
1002 1002
cm2
102 102
mm2
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Circles Diameter (D): The distance across a circle from one side to
the other, passing through the centre. Radius (r): The distance from the side of a circle to the centre.
Dr
Calculations for measurements involving circles involve a special number called π (pi pronounced pie).
The value of πis close to 3.14159… However, you should always use the πbutton on your calculator when calculating with πunless told otherwise.
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Circumference of a circle The circumference of a circle is the
distance around the outside (perimeter) of a circle.
The formula for the circumference of a circle is:Circumference =πx Diameter
=πDor
Circumference = 2xπxradius =2πr
To remember:
Twinkle, Twinkle little starCircumference of a circle is 2πr
C=2πr
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Area of a circle The formula for the area of a circle is:Area = πx radius x radius =πr2
Area =πx r x r
=πr2
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Calculate the circumferences and areas of the following circles.
a) b)
c) d)
8cm
13m
20mm
52km
Circumference and Area of a circle: Examples
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ClassworkYear 8Text: Cambridge Essential Maths 8: Chapter 4 Ex 4B Q5a,b,d,eEx 4E Q3, Q5a,d,e, Q6a,d,f
Remember to show all workingExtension:Ex 4B Q6Ex 4E Q
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Calculate the circumferences and areas of two circles below.a) b)
Circles: Exit questions
25cm 5km