Begin the session by showing students a strip of paper or a piece of masking tape stuck to the carpet that is a metre in length. Ask the students:
Challenge students to think about how they come up with their estimate.
Students get into groups of four to discuss and record their estimations. As a class, have groups report back on their 'estimates'. (Explain 'estimate' and alternate the word 'estimate' with the word 'guess' so students are clear about its meaning.) Emphasise the strategies used to make their estimates. Compile a class list of strategies used as well as the estimates given.
Adaptation for NESB students: Listen for the language the students already know and model the correct mathematical language when recording the strategies. For example, if 'bigger' is being used instead of 'longer', correct this. Listen for the language of comparatives and model language such as 'as long as' 'longer than' ' not as long as' 'shorter than', for example.
Ask the students how they could check the accuracy of their estimates. Ask students "With the measuring things or equipment we have in our room, which method will provide us with the most accurate answer?" This is the answer which is the right one. The accurate answer is the one which will always be the same. Students should be encouraged to see that a metre stick or ruler will provide them with an accurate, consistent, quick measurement.)
Measure the strip of paper/tape using the metre stick/ruler.
Now ask students to think about what could you do if you didn't have a standard measuring tool such as a ruler or a metre stick? This discussion should focus on the importance of students developing personal benchmarks for measuring lengths. Your questioning may need to be more specific by posing prompts such as "How could we use parts of our body to show 1 metre in length?"
Students get back into their groups of four. Provide each group with a metre length of paper or string. They will use this to experiment, finding 1 metre lengths on their bodies that could be used as personal benchmarks.
Adaptation for NESB students: Explain that these measurements can be used for each person as useful measurements. They are always the same for that person and are called 'benchmarks'. Discuss when a personal benchmark might be useful. For example, you are buying a new desk for your room and you wonder whether the one in the shop might fit, but you don't have a ruler.
Once students have recorded a number of possible personal benchmarks for 1 metre that could be used (for example, the length from their wrist to their shoulder, etc.) have them try to use it to find as many objects in the room/ playground/ school that are 1 metre long (for example, the length of two desk tops, the height of a computer table). Have them record the objects they find that they estimate to be 1 metre in length.
Published on: 09 Jan 2018
