In Maths this week, Year 3 are learning about angles and the properties of shapes which includes in today’s lesson how to measure and draw shapes accurately. We began with recapping on the basic rules of using a ruler and the children practised lining the ruler up along straight lines, beginning at the ‘zero’ rather than the edge and reading the scale in both centimetres and millimetres.
We were then given a strip of paper measuring 10cm x 29cm 7mm (the length of a sheet of A4 paper) and we had to measure 10cm along the top and make a mark, then 10cm along the bottom and make another mark. Once we had drawn a line to connect the marks, usually it was clear to see if the measurements were accurate because they would create a perfect square.
We repeated the measurements again and after cutting out both squares, we were left with three shapes. We were asked to compare our two 10cm squares and if they weren’t exactly the same, we were able to see that at least one of our measurements weren’t accurate. We were told what the measurements of our final shape should be and we measured it to check. As some of our measurements didn’t match up correctly, we took the opportunity to have a class discussion and reflect on why some measurements were not accurate and what we had to do to make sure they were.
For example, sometimes our hands would slip when holding the ruler, sometimes we misread the scales and on other occasions we weren’t as careful cutting with scissors as we could have been. This was a useful exercise to learn the importance of taking care handling the ruler and making precise accurate measurements to the nearest millimetre.
We then applied these skills to drawing right angle triangles with the lengths of two given sides. We had to measure the longest side to the nearest millimetre and if it wasn’t a specific length, we had to look back at the first two sides and work out what went wrong. The important thing was not to give up and move on but to try again until our measurements were exact.
