LI - to understand how to calculate elapsed time using a timer. To measure one minute of time using a formal unit To understand how estimation is important in mathematical investigations Let's look at this website. http://www.scootle.edu.au/ec/viewing/L9649/index.html How long is ONE MINUTE? I’m going to time one minute. When you think one minute has passed, sit down. Repeat and discuss. What else can you do in one minute? What do you know about the analogue clock? Hour hand, minute hand and second hand. Which hand moves fastest? How many times does the second hand move to complete a full circuit? There are 60 seconds in one minute.