Variables
 

Discussion - part 1

Pupils will have had experience of number sentences – sentences telling about numbers – from infants upwards. Their ideas of these might now be clarified through discussion. They will accept that sentences are used to communicate ideas orally and on paper. Examples such as “Galway is in Connaught” and “Dublin is in Ulster” will satisfy them that sentences may express true or false ideas.

They might here be given the term close sentence to refer to sentences like those above that may be true or false in contrast to the open sentence such as “ ______ is the capital of Ireland.” As it is here, this sentence may be true or false. It expresses a true statement if, and only if, we put the word “Dublin” in the frame. It expresses a false statement if we put the name of any other city in the frame.