International time difference II

International time difference II

Auto-markingPencil and paperOnline interactive
Overview
Using this Resource
Connecting to the Curriculum
Marking Student Responses
Working with Students
Further Resources
This task is about working with negative numbers and international time zones.
 
New Zealand (NZ) +12 Berlin (B) +2
Sydney (S) +10 Amsterdam (A) +1
Los Angeles (LA) -8 Moscow (M) +4
Vanuatu (V) +11 Ecuador (E) -5

The table shows how many hours each place is ahead of, or behind, Greenwich Mean Time (G.M.T).

Question Change answer

a)  On the time line below put in the code letter(s) of each place, showing its difference from G.M.T.
     Amsterdam (A) has been done for you.
Drag and drop image target

Question 2Change answer

a)  How many hours is New Zealand time ahead of Amsterdam time?   hours
b)  What is the time difference between Sydney and Moscow?  hours
c)  What is the time difference between New Zealand and Ecuador?  hours
d)  At 6:30 p.m. John, in New Zealand, phones his friend in Berlin. What time would it be in Berlin?
e)  If it is 2300 hours in Los Angeles, what is the time in Vanuatu?
Task administration: 
This task can be completed with pen and paper or online (with auto-marking).
Level:
4
Curriculum info: 
Maths, Geometry and Measurement, Measurement
Keywords: 
time, time-zones, negative numbers, 24-hour time
Description of task: 
Students answer questions about international time differences.
Curriculum Links: 
This resource can help to identify students' understanding of the measurement units of time for Measurement, and additive strategies (including negative numbers) for the Number and Algebra strand.
Learning Progression Frameworks
This resource can provide evidence of learning associated with
Additive thinking, sets 7-8
within the Mathematics Learning Progressions Frameworks.
Read more about the Learning Progressions Frameworks.
Answers/responses: 
 

Y8 (10/1997)
a) all 7 place names correct
 
5-6 place names correct		 7 correct – easy
 
5-6 correct – easy
b) 11 hours [12 - 1] easy
c) 6 hours (accept - ⁻6 hours) easy
d) 17 hours [12 - ⁻5]  (accept ⁻17 hours) moderate
e) 8:30 a.m. [6:30 p.m. - ⁻10] difficult
f) 6:00 p.m.  or 1800 hours [2300 + 1900 - 2400] difficult

time-zones-1.GIF

Diagnostic and formative information: 
  Common error Likely calculation Likely misconception
b) - f) Out by ± 1 hour.    
d) 7 12 - 5 Absolute time difference. Assumes Ecuador ahead of NZ time.
e) 4:30 a.m.
8:30 p.m.		 6:30 p.m. + 10 hr
6:30 p.m. + 2 hr		 Assumes Berlin ahead of NZ time.
Adds Berlin's time different from G.M.T.
f) 0400
4200
2319		 2300 - 1900
2300 + 1900
2300 + 19		 Assumes LA ahead of Vanuatu time.
Needs to subtract 1 day = 2400.
Adds time difference in minutes.