Two Clocks - Interactive activity to compare times


The two clock activity is a follow up to the clock activity. Using two clocks it is easier to explain time differences between a start time to an end time. The activity can also generate time problem questions at varying levels of difficulty.

Digital clocks

The two digital clocks match the analogue clocks below. You can change the format of the digital clocks. Click the 12 button to display in normal 12 hour format with AM/PM. Click 24 button to change to the 24 hour format. To hide the digital clocks press off .

Start, Duration and End Times

Two large face clocks can show independent times the left clock represents a start time, while the right clock represents an end time. When the activity starts both clocks display 9am. Click and drag the hour hand on the second clock forward. You will notice as you drag, the minutes and hours durations change too. You can also click these two controls and manually change the values and the second clock will update.

Now click the link toggle button, when on the clocks are linked. Now if you change one clock the other will adjust accordingly. Press reset and the the difference or duration between the two clocks is set to zero and if linked both will show the same time.

Random Times and hiding clocks

Click the random button and clock 1 will spin to a random time of the day. If the clocks are linked then the second clock will change according to the duration. This works well in tandem with hiding parts of the interface, so for example set the duration to 1hr 30mins and hide clock 2. Press the random button, clock 1 will now show a random time. The students can try to work out what the time is on the second hidden clock, which then can be revealed. Hide again and click random to repeat.

Real Time

To show the actual time on clock one turn on the real time control, if the clocks are linked then the second clock will update according to the duration. If not linked then the duration will update as clock1 ticks.

Generate time based question

The activity can generate random question at varying levels of difficulty. To do this click question a dialogue will open with one question. You will notice three buttons under the question, the click the first one labeled 'set up'. This will set the duration to zero and set both clocks to either the start or end time, based on which is revealed in the question. The clock hands can be dragged to solve the question, see the video for more information.

Click the 'solve' button and the clocks and duration will automatically be set according to the question. Click 'remove' to get rid of the question.

Multiple question can be created by clicking question more than once.

Question difficulty level

There are five difficulty levels the first two levels are most restricted

  1. All the times are start,end and duration whole hours
  2. Start and end whole hour, duration less than 60 minutes and easier numbers
  3. Still easier numbers to work with

Related activities

The clock whiteboard activity has just one clock, but it can be used to display fractions and angles too.

Digital Clock One - can change format using buttons
Digital Clock Two - can change format using buttons
Show digital clocks with 12 hour format
Show digital clocks with 24 hour format
Hide the digital clocks
Click to spin the hands of clock one to a random time
Display the time according to your computer clock
The number of hours difference between the two clocks
The number of minutes difference between the two clocks
Click to toggle linked clocks, when linked changing one will change other
Click to set to reset the hour and minute duration to zero.
Click to show or hide the first clock
Click to show or hide the second clock
Click to show or hide the duration controls
Generate a question
Set the difficulty of the generated question.