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).
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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