This is the second of three articles that draw on findings from Nunes, Watson and Bryant (2009): "Key understandings in school mathematics: a report to the Nuffield Foundation". The report was soundly based on research about how children learn mathematics, much of it done in the UK in the '80s. Most of the findings about algebra are very…

Repeatedly taking the square root with a calculator yields numbers with logarithmic-type properties, which can be used to define the logarithm functions. (MP)

Four categories of abuses are discussed: calculations, games and puzzles; mystical button pushing; and checking answers. Useful activities are illustrated for the categories of calculations, patterns, exploration, applications, and new content. (MP)

Problems arising from using a calculator are discussed, and some mathematics activities involving calculators are suggested. (DT)