The idea, step by step
Work backwards from a deadline
A feasible plan can really be followed with the information given. List fixed times, such as an appointment or a bus departure. List durations, such as a walk or a check-in. Work backwards from the deadline to find when the journey must begin.
For an appointment at 10:15 with a 35-minute trip and a 10-minute check-in, allow 45 minutes altogether. Leaving at 09:30 gets you there at 10:05 and ready by 10:15. A small buffer would make the plan more reliable.
Check the complete journey
Add travel, activities and waits. Check that the total fits inside the available time and that each connection is possible. Check the return journey too: arriving at the activity on time is not enough if the return is too late.
Compare plans using the actual goal. The quickest travel time, earliest arrival, lowest cost and most spare time can select different plans. Give a reason that matches the goal rather than simply saying a plan is better.
A common trap
Adding only the time spent at the destination and leaving travel or waiting out of the plan.
Instead: Account for every part, including the return trip and required transfer or check-in time.
See the thinking
Latest departure
An appointment begins at 10:15. Travel takes 35 minutes and check-in takes 10 minutes. When must you leave at the latest?
- Total time needed: 35 + 10 = 45 minutes.
- 10:15 minus 15 minutes is 10:00; subtract another 30 minutes.
Fit an outing into a morning
An outing can run from 09:00 to 12:00. Travel out takes 30 minutes, a visit takes 60 minutes, a walk takes 15 minutes, a park stop takes 45 minutes and travel home takes 30 minutes. Does it fit?
- Available time is 3 hours = 180 minutes.
- Needed time is 30 + 60 + 15 + 45 + 30 = 180 minutes.
- A plan is 09:00–09:30 travel, 09:30–10:30 visit, 10:30–10:45 walk, 10:45–11:30 park, 11:30–12:00 home.
Check your understanding
A 90-minute visit and two 20-minute journeys must fit into 2 hours. Is this possible?
Show answer
No.
90 + 20 + 20 = 130 minutes, which is 10 minutes more than 120.
Your turn
6 questions · 13 marks · Work at your own pace.
Read the questions online
- A lesson starts at 14:20. Travel takes 25 minutes and settling in takes 5 minutes. Find the latest departure.2 marks
- A walk takes 18 minutes. A bus leaves at 11:25. If you leave home at 11:04, how much time is left before departure?2 marks
- An outing has parts lasting 25, 40, 15 and 30 minutes. It must fit into 2 hours. How much spare time is there?2 marks
- A trip begins at 09:00. Plan A takes a 30-minute bus, a 10-minute wait and a 15-minute walk. Plan B takes a 20-minute bus, a 25-minute wait and a 15-minute walk. Which arrives earlier, and by how much?3 marks
- You must be home by 14:00. A tour has return options arriving at 13:45 and 14:10. Which meets the deadline, and how much time does it leave?2 marks
- A plan lasts exactly 150 minutes, the whole available window. Give one reason it may be risky, and one sensible change.2 marks
Read the worked solutions
Equivalent correct methods earn the corresponding marks. Include units where asked.
- A lesson starts at 14:20. Travel takes 25 minutes and settling in takes 5 minutes. Find the latest departure.2 marks
25 + 5 = 30 minutes.
14:20 − 30 minutes = 13:50.
13:50 - A walk takes 18 minutes. A bus leaves at 11:25. If you leave home at 11:04, how much time is left before departure?2 marks
11:04 + 18 minutes = 11:22.
11:22 to 11:25 is 3 minutes.
3 minutes - An outing has parts lasting 25, 40, 15 and 30 minutes. It must fit into 2 hours. How much spare time is there?2 marks
25 + 40 + 15 + 30 = 110.
120 − 110 = 10 minutes.
10 minutes - A trip begins at 09:00. Plan A takes a 30-minute bus, a 10-minute wait and a 15-minute walk. Plan B takes a 20-minute bus, a 25-minute wait and a 15-minute walk. Which arrives earlier, and by how much?3 marks
A takes 55 minutes and arrives at 09:55.
B takes 60 minutes and arrives at 10:00.
Plan A arrives 5 minutes earlier. - You must be home by 14:00. A tour has return options arriving at 13:45 and 14:10. Which meets the deadline, and how much time does it leave?2 marks
13:45 is before 14:00.
14:10 is too late.
14:00 − 13:45 = 15 minutes.
The 13:45 option, leaving 15 minutes. - A plan lasts exactly 150 minutes, the whole available window. Give one reason it may be risky, and one sensible change.2 marks
There is no spare time.
A suitable change creates a buffer without ignoring a fixed appointment.
A delay could make the finish late. Shorten an optional activity or allow a longer window.
Curriculum reference & lesson scope
Australian Curriculum v9 / SA Curriculum Mathematics
Year 6: itineraries, elapsed time and feasible journey planning, including connections and 24-hour time.
Official curriculum source ↗