Presents a technique for multiplying two-digit numbers whose tens digits are equal and whose units digits have a sum of 10. Then various mental calculations with other types of two-digit and larger numbers are discussed. (MNS)

Included in this section are brief articles outlining an approach to teaching mental computation, an inductive approach to algebra, and using football to teach probability. (MNS)

The difference between estimation (the mental skill of making an educated guess) and approximation (finding a result precise enough for a specific purpose) is discussed. (MNS)

Discoveries of Charles Babbage in the 1800s are described. Origins of the difference engine, his calculating machine, the principles of computation applied to tables, and the design and construction of his engine are included. (MNS)

The calculator is used to obtain values for use in graphing curves. Three worksheets are included. (MP)

Ways of using the calculator as a vehicle for investigating one aspect of the square root concept are illustrated. (MK)

An example is given of a class of problems whose solutions require the use of a scientific calculator in order to plot the graphs. (MP)

Described is a calculator race that is designed to require a fast touch with the calculator and also the ability to apply mathematical knowledge. Sample questions are given. (MP)

Shortcuts to use when performing operations with the calculator are given. Algorithms discussed include reciprocals, powers, parentheses, infinite series, and synthetic division. (MP)

Offers examples of loss of accuracy when using digital computing devices. Discusses causes for loss of accuracy and methods of preventing loss. Presents implications that loss of accuracy has for mathematics instruction. (MDH)

Ten problems involving large calculations are described for classroom use with a calculator. (JT)

A drill-and-practice game called "Digits Delight"; the story of Parabella (and Hyp and Elli); and a method for finding inverse functions, using Rubik's cube and algebra, are included. (MNS)

Comments on the history of negative numbers, some methods that can be used to introduce the multiplication of negative numbers to students, and an explanation of why the product of two negative numbers is a positive number are included. (MNS)

Several subtraction algorithms are analyzed to see if they involve borrowing. The main focus is on an analysis of a procedure called the residue method. The operational arithmetic which underlies the symbolic manipulations is examined and conditions where the method does and does not use borrowing are highlighted. (MP)

Four problems are presented and solutions using a calculator are illustrated. (MK)