What does a child have to do to calculate a duration in the 11+?

Find elapsed time between two clock or timetable entries. It is one of 55 named maths skills in the 11+, in the measure strand, and this page carries 1 interactive exercise that practises it.

What is the trap in an 11+ calculate a duration question?

An hour is 60 minutes, so the digits on a clock cannot be subtracted the way ordinary numbers are. The wrong answers on this skill are built out of that, not out of random numbers, so it is worth naming out loud before your child meets it under time pressure.

What can I say if my child is stuck on calculate a duration?

Point at the next move rather than explaining the whole rule. Count on from the earlier time to the next whole hour, then on to the later time, and add the two counts together.

What is not part of calculate a duration in the 11+?

The skill map draws the line here: One continuous interval. A question past that line is testing a different named maths skill, which is worth knowing before you spend a week practising the wrong one.

Which other 11+ skills should we practise alongside calculate a duration?

The measure strand holds 4 skills that are tested together, and the pages next to calculate a duration are calculate perimeter, convert units and calculate area. Each has its own exercise and its own link, and none of them needs an account.

How can my child practise calculate a duration for free?

Use Clock & Coins, embedded on this page. It is the exercise the skill map attaches to calculate a duration, it runs in the browser with no account to make, nothing is scored, and nothing a child does here is recorded or sent anywhere. It also has its own link, so you can send it to a child without sending them anywhere else first.

Maths · Measure

Calculate a duration

Find elapsed time between two clock or timetable entries.

Practise it now

The football match starts 1h 20m after 08:05. Wind the clock forward to find out when.

It covers most of this skill rather than all of it.

Loading the interactive exercise. Nothing you do here is saved or scored.

A worked example

One question of the kind this skill is tested with, worked all the way through: the reasoning, and what the wrong answers are there to catch.

Counting minutes between two clock times

How many minutes are there between the Start time and the Finish time for Football?

Sessions at the half-term holiday club.

Football

Start time: 13:54
Finish time: 14:14

Baking

Start time: 15:45
Finish time: 16:32

Swimming

Start time: 09:46
Finish time: 10:30

Session	Start time	Finish time
Football	13:54	14:14
Baking	15:45	16:32
Swimming	09:46	10:30

60 minutes
40 minutes
80 minutes
20 minutes

Answer: 20 minutes

How you get there

The clock passes 14:00 on the way, so counting on from 13:54 to 14:00 and then on to 14:14 is what keeps the hour honest: 13:54 to 14:14 is 20 minutes, so Football takes 20 minutes. Taking one clock reading away from the other as if they were ordinary numbers gives a different answer, because an hour is 60 minutes and not 100.

Why the other answers tempt

An hour is 60 minutes, so the digits on a clock cannot be subtracted the way ordinary numbers are.

If they are stuck, say this

Count on from the earlier time to the next whole hour, then on to the later time, and add the two counts together.

Now do it live in Clock & Coins

Kitchen-table script for parents

Try this together

A friendly mini script for the breakfast table, school run or a quiet two minutes. Read it aloud as written, or make it your own.

Ready? Let's try Calculate a duration together. Take a look at the picture. Here is what matters: Rows: Session Football, Start time 13:54, Finish time 14:14; Session Baking, Start time 15:45, Finish time 16:32; Session Swimming, Start time 09:46, Finish time 10:30. Here comes the question: How many minutes are there between the Start time and the Finish time for Football? A handy clue is: Count on from the earlier time to the next whole hour, then on to the later time, and add the two counts together. Nice work. Here is the thinking: Taking one clock reading away from the other as if they were ordinary numbers gives a different answer, because an hour is 60 minutes and not 100. So our answer is: 20 minutes. One sneaky trap is: An hour is 60 minutes, so the digits on a clock cannot be subtracted the way ordinary numbers are. Can you show me the first move in your own words? No rush; one calm step is enough.

What this exercise is doing

Clock & Coins

The football match starts 1h 20m after 08:05. Wind the clock forward to find out when.

Winding forward 1h 20m from 08:05 lands on 09:25 - the hour hand moves too, one twelfth as fast as the minute hand, which is why it sits between the numbers. Then 30p takes at least 3 coins from this tray: there is no 10p in it, so you have to build the amount from what is actually there.

Step 1. Wind the clock. Wind the minute hand forward 1h 20m from 08:05.
Step 2. Count the coins. A programme costs 30p. Drag coins into the purse to pay it exactly.

What to say if they get stuck

Grab the long minute hand and wind it forwards. Watch the little hour hand creep round with it.
One whole lap of the minute hand is one hour. You need 1h 20m.
For the coins, start with the biggest coin that fits inside 30p and keep going.

Open Clock & Coins on its own page to share it

How calculate a duration differs from the skills beside it

The same exercise practises several skills, and telling them apart is often the difficulty rather than the exercise itself. On this page the skill is: find elapsed time between two clock or timetable entries, and it stops where one continuous interval.

Convert units
Convert one measure between compatible metric or time units. The quantity type and units are stated.
Solve a one-step number problem
Choose and perform one operation in a short context. Exactly one operation is required.

Related maths skills

Calculate areaCalculate the area of a rectangle or decomposable rectilinear shape.
Calculate perimeterCalculate the boundary length of a labelled rectilinear or polygonal shape.

All maths 11+ skills

Questions parents ask about calculate a duration

Answered from what the skill map records about this skill, not from a template. Every answer here is on the page, and the same questions are the page's FAQ structured data.

: Find elapsed time between two clock or timetable entries. It is one of 55 named maths skills in the 11+, in the measure strand, and this page carries 1 interactive exercise that practises it.
: An hour is 60 minutes, so the digits on a clock cannot be subtracted the way ordinary numbers are. The wrong answers on this skill are built out of that, not out of random numbers, so it is worth naming out loud before your child meets it under time pressure.
: Point at the next move rather than explaining the whole rule. Count on from the earlier time to the next whole hour, then on to the later time, and add the two counts together.
: The skill map draws the line here: One continuous interval. A question past that line is testing a different named maths skill, which is worth knowing before you spend a week practising the wrong one.
: The measure strand holds 4 skills that are tested together, and the pages next to calculate a duration are calculate perimeter, convert units and calculate area. Each has its own exercise and its own link, and none of them needs an account.
: Use Clock & Coins, embedded on this page. It is the exercise the skill map attaches to calculate a duration, it runs in the browser with no account to make, nothing is scored, and nothing a child does here is recorded or sent anywhere. It also has its own link, so you can send it to a child without sending them anywhere else first.

Knowing which maths topic to practise is most of the work

A free diagnostic covers arithmetic, fractions, geometry, measure and data handling, and comes back with the topics to spend the next few weeks on.

Start the free 11+ diagnostic