11 plus Time & Timetables questions

What a Time & Timetables question looks like

Time & Timetables sits in the measurement part of 11 plus maths, and it covers more ground than the name suggests. Some questions give a clock time and ask for it in the other format: 3:45 pm written as 15:45, or 19:15 written as 7:15 pm. Some give a start and a finish and ask how long something lasted. Others give a start and a duration and ask for the finish, or a finish and a duration and ask for the start. A few ask what day of the week a date falls on, or read a clock face, or turn 2 hours 15 minutes into 135 minutes. Around a fifth of them are built on a printed timetable.

The nearest neighbour is Units & Conversion, which also moves between one unit and another. The difference is where the difficulty lives: Units & Conversion works by multiplying and dividing by 10, 100 and 1,000, whereas time carries at 60 minutes and starts again at midnight, and no other maths topic asks a child to read a grid of departure and arrival times.

Example one: how long did it last

A radio programme runs from 06:45 to 09:10. How long is the programme?

Count up in steps, never as a subtraction sum. From 06:45 to 07:00 is 15 minutes. From 07:00 to 09:00 is 2 whole hours. From 09:00 to 09:10 is 10 minutes more. Add the two lots of minutes: 15 and 10 make 25.

The answer is 2 hours 25 minutes.

Check it by putting it back: 06:45 plus 2 hours is 08:45, and 08:45 plus 25 minutes is 09:10. The wrong answer that catches children here is 2 hours 15 minutes, from counting the 15 minutes up to 07:00 and the 2 whole hours after that, then stopping before the last 10 minutes. Every step is right except the one left out, which is why it feels finished.

Example two: reading a timetable

Ellie has to be at Kingsbridge by 09:00. Which is the latest train she can catch from Millfield?

The word to hold on to is “latest”, so start at the right-hand side and work left. Service 4 leaves Millfield at 08:35 and reaches Kingsbridge at 09:18, after 09:00, so it is out. Service 3 leaves at 08:05 and reaches Kingsbridge at 08:48, before 09:00.

The answer is the 08:05.

Two wrong answers are built into a question of this shape. One is 08:35, chosen by a child who reads “latest”, picks the last departure and never follows the column down to the Kingsbridge row. The other is 08:48: the right service, but a train is named by the time it leaves, not the time it arrives.

Example three: crossing midnight

A television programme starts at 22:50 and lasts 1 hour 35 minutes. What time does it finish? Give the answer in 24-hour clock.

Do the hour first and the minutes second. 22:50 plus 1 hour is 23:50. Now the 35 minutes, in two pieces: 10 minutes takes you to 00:00, which is midnight, and the 25 minutes left over takes you to 00:25.

The answer is 00:25.

Two wrong answers sit close to it. 23:85 comes from adding 35 to 50 and writing the 85 straight into the minutes, which is not a time at all, because the minutes never go past 59. 01:25 comes from counting the hour twice, once when it was added and once when the clock rolled over at midnight.

How to answer it

1. Work out which of the three jobs you have: a duration (start and finish given), a finish (start and duration given) or a start (finish and duration given). The third, working backwards, is the one children rush.
2. Put both times into the same format first. Add 12 to the hour to make a pm time into a 24-hour time, so 2:30 pm is 14:30. Take 12 off the hour to go back the other way, so 14:30 is 2:30 pm.
3. Count in steps. Go up to the next o’clock, then in whole hours, then the minutes left over, and add the two lots of minutes at the end.
4. Watch the two roll-overs. Sixty minutes make an hour, so 09:75 and 3:70 pm are not times. Midnight ends the day, so 23:45 plus 1 hour 20 minutes is 01:05 the next morning, not 24:65.
5. Put the answer back into the question before choosing it. If the programme finished at 00:25, take the 1 hour 35 minutes off again and see whether you land back on 22:50.

Common mistakes

• Writing a time that cannot exist. 09:75, 11:95, 3:70 pm and 23:85 all come from pushing the minutes past 59 without carrying into the hour. Scanning the options rules these out before any working is done.
• Taking one time away from the other as if they were plain numbers. 15:11 take away 14:25 is 46 minutes, not 1 hour 6 minutes. The clock carries in sixties, so counting up in steps is the only safe route.
• Picking the latest departure instead of the latest one that works. On a “which is the latest train” question the answer is hardly ever the last column, because these questions are set so that the last service arrives just too late.
• Forgetting the break. A child working from 16:30 to 18:15 with a 20-minute break in the middle has worked for 1 hour 25 minutes, not the 1 hour 45 minutes the clock times give on their own.
• Missing that the day has changed. A flight leaving at 22:00 on Tuesday and lasting 9 hours lands at 07:00 on Wednesday, not Tuesday. An answer with the wrong day on it looks right at a glance.

How to practise 11 plus Time & Timetables questions

Time is the eleven plus topic your child meets outside the exam room most often, and that is the way in. A printed bus timetable costs nothing and children take it more seriously than a worksheet, so two questions of your own (“we need to be there by four, so which one do we get?”) go a long way. Beyond that it is habit: counting up through the hour rather than subtracting, and checking an answer by putting it back. Short and regular beats long and occasional, which is the pattern we set out in how much 11 plus practice a child needs each day. When one comes back wrong, ask your child to say the time aloud rather than read the digits, because “ten to nine” and 08:50 sit in different parts of a child’s head and the mistake is usually in the join. 11+ Daily has a Time & Timetables project alongside the rest of the 11 plus maths practice topics, on laptop, tablet or phone. Every question is original to 11+ Daily, nothing is a past paper and nothing is licensed from another publisher, and the bank is re-checked in rounds.

Questions parents ask