MEASUREMENT 1.3Internal 3 Credits

Achievement Criteria Explanatory Notes

Solve a problem(s) involving measurement of everyday objects.

Students are required to choose, and make, appropriate measurements. Appropriate use of equipment is implied by a reasonable measurement. Students are expected to use their measurements in solving a problem.Everyday objects will be based on circles, triangles, rectangles, cuboids, cylinders and triangular prisms. Combinations of these may be assessed.

Solve measurement problems.

Problems will be based on a representative selection involving perimeter and circumference, area (including surface area), volume, mass, capacity and time (including 24-hour clock time).

Achi

evem

ent

Metrics - RevisionBase Units: metre (m) - length

litre (L) - capacity (volume)gram (g) - mass (weight)

Prefixes: milli (m) - 10001

centi (c) - 1001

deci (d) - 101

deca (D) - 10hecto (H) - 100kilo (k) - 1000mega (M) - 100000

*

*

*

* commonly used ones

WHICH UNIT DO I USE FOR LENGTH?

Unit symbol Used for Example

millimetres mm very accurate measurements

pencil lead is 0.5mm thick

centimetres cm approximate measurements

my height is 173 cm

metres m buildings, sport a rugby field is 100m

kilometres km distances it is 5 km to Pakuranga

WHICH UNIT DO I USE FOR WEIGHT?

Unit symbol Used for Example

milligrams mg very accurate measurements

50mg of caffeine in coffee

grams g approximate measurements 50 grams of butter

kilograms kg people, objects that can be carried

I weigh 65 kg

tonnes t heavy objects a truck weighs 6 tonnes

Revision - Metric ConversionsWhen changing to a larger unit, move the decimal point to the left. How far left depends on the number of zeros in the prefix value.

Examples: 4321 mm = 4.321 521 g =

mkg0.521

62.1 mm = cm6.21

When changing to a smaller unit, move the decimal point to the right.

Examples: 524.3 m = cm5243004218.4 kg = g0 0 4218400

5.24 cm = mm52.44.321 km = cm 00 432100

÷ 1000÷ 1000÷ 10

x 100x 1000

x 1000 x 100x 10

VOLUME What do you think volume is? The volume of an object is a measure of how

much space it occupies. Anyone know how it is measured? Cubic units:

Cubic metresCubic centimetresCubic millimetres

m3

cm3

mm3

DIFFERENT VOLUMESThis is one cubic centimetre

1 cm3

This is one cubic millimetre

1 cm = 10 mm

10 mm

10 mm

This is one thousand cubic millimetres.

10mm x 10 mm x 10 mm = 1000 mm3

PRISMS What is a prism? A object with parallel sides that are

right-angles to each end. Rule is that each end has the same

shape and size.

VOLUME

Area of the end = 12 x 10 = 120 cm2

Volume = 120 x 15 = 1800 cm3

Volume of uniform solid = area of end x length

or= area of end x height

Solids of uniform cross-section

height

end lengthend

PRISMS - VOLUME Area of side = 37

cm2

Length (or height) = 5 cm

What is the volume?

What units?

37 cm2

5 cm

EXAMPLE EXERCISE What is the

volume of this rectangular block in mm3 and cm3?

Volume = l x w x h Try it. 60 mm

39 mm

24 mm

EXERCISE Calculate volume

of cylinder. Volume = ? Volume = r2 * h Calculate to 4 s.f.

r = 1.9m

h = 4.7m

PRACTICE EXAMPLES Do exercise 13.01

1 a, b 2 b 4 a 5 a, b, d, e 6 a, b 7 a, b 8 c 11