1. Fractions and decimals
N2.3 Extension Starter
Strips of paper
Part of this strip of paper is shaded.
Just by folding (no measurements allowed) how can you find out what fraction of the whole strip is shaded?
Work out how to fold a strip of paper into three equal parts without measuring.
How could you use your method to help you divide a strip of paper into sixths?
Preamble A mental/visualisation activity which requires pupils to fold paper strips into given fractions. It is also a good opportunity for pupils to practise their oral skills. Stress the importance of visualisation. The first part should not present too many problems, but dividing a strip into three equal parts, in preparation for dividing the strip into six, is by no means self-evident. According to circumstances, allow pupils to try their methods practically – perhaps as a homework.
Possible content Fractions of a whole by folding.
Resources
Possibly wide strips of paper and a ruler (to check accuracy of the method), if it is felt useful for pupils to try out the methods practically.
Solutions/Notes An odd number of folds is easily achieved
by folding strips of paper gently and then
firmly, as shown in the diagram. You could ask pupils to measure their strips to check the accuracy of their method.
Folding the strip in half at right angles to the folds will give sixths. A similar method can be used to divide a strip into, for example, five and ten parts.