The basis of this intervention study is a distinction between numerical calculus and relational calculus. The former refers to numerical calculations and the latter to the analysis of the quantitative relations in mathematical problems. The inverse relation between addition and subtraction is relevant to both kinds of calculus, but so far research…

Examples are given of transcripts made from tape recordings of a teacher working with groups of 10-year-old children using calculators. Attention is focussed on the teacher's role in the interactions which take place. Suggestions are offered for the possibility of a structure of strategies available to a teacher. (Author/RH)

Studied for three years were eight Swedish classes with pupils aged 10-12 using calculators whenever they could be of use, along with experimental textbooks. The experimental classes were as competent as control classes in mental arithmetic and calculations with simple algorithms, and had better understanding of numbers and problem solving. (MNS)

The importance of teaching computational estimation is discussed, with note of its increased significance because of widespread use of calculators and the need to develop number sense. The reason for its failure to be taught is traced to the multiplicity of methods, and some detailed suggestions are therefore presented. (MNS)

Offers 3 teaching designs developed for 12- to 16-year-old pupils taking into account personal differences in gender, culture, knowledge, and use of calculators. The designs concern the representation of three-dimensional objects in the plane, directions and great circles on the sphere, and exploration of the integrating calculator. (Contains 31…