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Hong Kong
Stage 1 - Stage 3

Estimate Lengths


Estimating length is an important life skill. Not only does it help when you want to have a good idea of how far away something is, or how long, wide or tall some object could be. It is also important in common practical circumstances like moving furniture into a room, how much wrapping paper you might need to wrap a present, or how far apart to plant your seedlings in the vegetable patch.  

There are two parts to good estimations involving length:

  1. Know what the best units of length would be to use
  2. Be able to estimate an appropriate size.

To get good at these, try and find some baseline lengths that are familiar to you. For example, ask yourself:

  • What common everyday object do I know that is about 1cm or 1m long? 
  • How far is it from my house to the end of the street?  

Then, when you need to estimate you could think about the estimation in terms of distances you are familiar with.  

Worked Examples

Question 1

Choose the best estimate for the length of a classroom.

  1. $4$4 metres.


    $60$60 metres.


    $100$100 metres.


    $10$10 metres.


Question 2

Estimate the height of a desk.

  1. $0.11$0.11 mm


    $110$110 mm


    $1.1$1.1 metres


    $1100$1100 cm



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