Missburkerocks.wordpress.com Measurement Year 7 & 8.

missburkerocks.wordpress.com

Measurement

Year 7 & 8


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).


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


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)

missburkerocks.wordpress.comLength Conversions


ClassworkYear 7Text: Cambridge Essential Maths 7: Chapter 11Ex 11B Q4a-f, 5a-c, 6g-h, 7a-f, 10a, b, 12, 13, 17, 19


Length Conversion: Exit questions

Complete the following metric conversions.

a)38m=__________ kmb)24cm=_________mmc)49cm (m)d)380m (mm)


Geometric symbols A box in the corner of

an angle denotes a right angle

Similarly marked segments are congruent (the same length)


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


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


Calculating Perimeter


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


Perimeter: Exit questions

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!


Calculating Areas of 2D shapes


Area (Year 7&8)

missburkerocks.wordpress.comArea (Year 8)


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


Write the formulae for the following shapesa) b)

c) d)

e) f)

Area: Year 7 exit questions


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!


Area continued From this you can create an area

conversion chart:km2

10002 10002

m2

1002 1002

cm2

102 102

mm2


Area conversion


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.


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


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


Calculate the circumferences and areas of the following circles.

a) b)

c) d)

8cm

13m

20mm

52km

Circumference and Area of a circle: Examples


Area of a circle


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


Calculate the circumferences and areas of two circles below.a) b)

Circles: Exit questions

25cm 5km


Area of a circle


Areas of composite shapes


Areas and perimeters of sectors A sector is a portion of a circle enclosed

by two radii.

Missburkerocks.wordpress.com Measurement Year 7 & 8.

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