This displays rulers used for measuring and a variety of mistakes that students often make.

• On the first page, use the rulers to point out that objects being measured need to be placed with the left-hand side at the 0 mark and then the scale is read at the right-hand side of the object.
• Use the rulers and shells on page 2 to discuss how errors in measurement can occur and how measuring incorrectly can produce misleading results.

Scallop 1 shows a shell measured from 1 rather than 0.

Scallop 2 shows a shell measured from the edge of the ruler rather than 0.

• You might choose to extend students who are able to measure competently by giving them the third sheet of this activity. Scallops 3 and 4 are measured against a broken ruler. Students will come to realise that although in the first example the broken ruler is numbered from 3. Since, this is actually the starting point for measuring it acts as the 0 on an unbroken ruler. Students could find the actual measurement by counting on from 3 in 1 cm increments or by using a basic fact, such as 3 + ? = 12.

This displays the Getting started on page 203 of the Student Resource Book.

• Encourage students to identify and give examples of
  • what is being measured - length, weight, capacity, volume, area, temperature
  • how it is being measured - ruler, measuring spoon, cup or jug, scales or thermometer
  • the units being used - millimetre, centimetre, gram, kilogram, millilitre, litre, degrees Celsius.

This displays three balances showing less than, equal to, and greater than 1 kg (as a block of cheese). Students must decide which balance will correctly show the weight of a food placed on the other side.

• You could extend the discussion for some students by asking which foods could be combined to achieve balance (B). For example, 4 punnets of 250 g strawberries would have the same weight as 1 kg of cheese, or 2 blocks of cheese and a 500 g block of butter would weigh the same as a 2.5 kg bag of flour.
• The discussion could be followed by asking students to work in groups to create similar balances using pictures of everyday foods from supermarket mail outs.

This displays two glasses – one filled to capacity and the other half full. Students are asked to use the image to explain what ‘filled to capacity’ means and determine the volume of water in a half-full glass.

• ‘Brim’ may be vocabulary that is unfamiliar to students, so you could use this sheet to extend their vocabulary and help students to recognise that filling containers to the ‘brim’ means the same as filling containers to capacity. You could discuss why glasses and cups are not usually filled to the brim.

• Encourage students to share their strategies for working out the area and volume in each task, but particularly where they are finding the combined total of the area covered or the box filled. When all the strategies have been shared, ask them to decide which strategy was most efficient.