Writing standard form

Writing standard form

Pencil and paper
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This task is about writing numbers in ordinary form and standard form.
 
Write each of the following numbers in standard form.
 
a)

 
The deepest part of Lake Manapouri is about 443 metres
 
= ____________________ metres

 


 
b)
The number of letters posted in New Zealand each year is about
 
818,900,000 = ____________________
 
 
 
c)
The population of New Zealand is close to 5.5 million
 
= ____________________
 
   
 
d) 
The thickness of fine wool is about 0.00002 metres
 
= ____________________ metres
 
 
e) 
A racing car can travel a metre in 0.012 seconds
 
= ____________________ seconds
 
Task administration: 
This task is completed with pencil and paper only.
Level:
5
Curriculum info: 
Maths, Number and Algebra, Number Knowledge
Keywords: 
standard form, place value
Description of task: 
Students convert numbers from ordinary form to standard form.
Answers/responses: 
  

Y10 (09/1999)
a) 4.43 × 102  [Accept 4.4 × 102.] moderate
b) 8.189 × 108  [Accept 8.1-8.2 × 108.] difficult
c) 5.5 × 106 difficult
d) 2.0 × 10-5  [Accept 2 × 10-5.] difficult
e) 1.2 × 10-2 difficult
Diagnostic and formative information: 
   Common error Likely reason
b) 
d) 
e) 		 8189 × 105
0.2 × 10-4
0.12 × 10-1		 Correct number but not in standard form.
d) 
e) 		 2 × 105
1.2 × 102		 Gives positive rather than negative exponent.
c) 4.1, 4.1 × 100
4.1 × 105 or 4.1 × 107		 Ignores million. 
Wrong size of 1 million (106). 
b) 
d) 		 8.189 × 105
2 × 10-4		 Gives the number of trailing zeros. 
Gives the number of zeros after the decimal point.