1. ©G Dear 2010 – Not to be sold/Free to use
Applied Mathematic
(Preliminary General 1)
Measurement
Managing Error
Stage 6 - Year 11
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©G Dear 2010 – Not to be sold/Free to use

2. Measure! Measure! Measure!
Reducing Error
When objects are measured their
is always some amount of error.
To reduce the error we must . . .
Measure!
Measure!
Measure!

3. Blood Pressure Measure your blood pressure three times.
Reject the extreme value.
Average the other readings.
Systolic
Diastolic
Sys = ( ) ÷ 2 =
134
Dia = ( ) ÷ 2 = 75

4. Measuring Area
Get 3 students to measure the dimensions of a book in cm. (Enter in table above.)
Soft Keyboard

5. Actual Length lies between
Degree of Accuracy
All measurements are accurate to within ± 0.5 of the smallest unit on the measuring device.
= 4 cm
Error = ±0.5 cm
Actual Length lies between =
4.5cm
4 – 0.5 =
3.5cm

6. What decree of accuracy would be needed when measuring a … ?
Degree of Accuracy
What decree of accuracy would be needed when measuring a … ?
a) Lighthouse
b) Soccer ball
metres
centimetres

7. Degree of Accuracy
Between what two limits does 75m lie if measured with a trundle wheel to the nearest metre?
Error = ±0.5 m
Lower = 75 -
0.5
= 74.5 m
Upper = 75 +
0.5
= 75.5 m

8. Degree of Accuracy
Between what two limits does 360cm lie if measured with a decimetre tape to the nearest 10cm?
Error = ± 5 cm
Lower = 360 - 5
= 355 cm
Upper = 360 + 5
= 365 cm
Decimetre tape

9. Degree of Accuracy
Between what two limits does 500 km lie if measured with a odometer to the nearest 5km?
Error = ± 2.5 km
Lower = 500 -
2.5
= km
Upper = 500 +
2.5
= km
Odometer

10. Degree of Accuracy
A building’s height was measured as 93 metres to the nearest metre.
Between what limits does it lie?
Range = 93 ± 0.5 metres
Between
92.5m and 93.5 m.

11. Degree of Accuracy A ball was measured as 80cm to the nearest 10cm.
Between what limits does it lie?
Range = 80 ± 5cm
Between
75cm and 85 cm.

12. Degree of Accuracy
The distance from Port Macquarie to Sydney is given as 500km
to the nearest
100km.
Between what limits does it lie?
Range = 500 ± 50km
between
550km and 650km.