15 May 2008

Measuring Up.....

One of today's challenges began with us finding a way to measure the classroom.  We knew that it was either a rectangle or a square (which meant that opposite sides were the same length).  We were going to make a scale drawing of the classroom and so to begin with wanted to find out (to the nearest metre) how many metres across it is and how many metres down.  We decided that we would do this using metre sticks.

In small groups we set about the task; which was made a little tricky because the arrangement of furniture is such that there are not many places where you can get right up to the walls on opposite sides of the room.  But with a bit of shoving and heaving we managed!


We quickly realised it was important to make sure we marked each metre so that when we moved the metre stick, we would know where to put it next.


When we compared results, they were a little surprising (with measurements ranging as they did from 6 metres to more than 8 metres!) and mean that we either need a bit more practice at measuring; or to find a way of making sure we do not lose count.....

However, after one final check, we all agreed that, to the nearest metre the classroom measures 8 metres across in one direction and 8 metres down in the other.


That makes it a square.

Then, just as we did yesterday, we took a piece of centimetre squared paper.  We were going to measure and cut out a square that was exactly the same as the classroom, just smaller.  One of the sides of the small squares on the paper would represent 1 metre in real life.  That is the scale of the square we made.  1cm = 1metre

So we would need to make our paper square 8cm across and 8cm down.

 IMG_5742 IMG_5744

Next we were asked to find out how many of the centimetre squares there were in our cut-out square.  Like a flash, Justin had the answer.  64.  And, even though counting is a pretty good way to find out the answer to a how many? question, he was too fast to have done that.  He had realised that 8 rows of 8 squares was the same as saying 8 x 8.  And he knew that 8 x 8 = 64.  WOW! 

Now here comes the really fancy stuff - along with something to think about.  We made a square using 4 metre sticks.  


(By the way, we learned that a square this size has a special name.  It is called a square metre.  We easily guessed why!)

Here comes that question:  If our classroom measures 8 metres across and 8 metres down, how many of those square metres would fit on the floor of the classroom? 

Think..... 8 rows of 8 squares.  I wonder; maybe you could use your scale drawing of the classroom to help.

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