AKA: OPERATORS HANDBOOK, BASIC COURSE, Product number (P/N): 993S (993/S),
Keywords/Tags: 993S (993/S)
Dimensions: 297x210mm,
Classification: / Documentation / Instructions,
#Pags: 19,
Info: The ‘Operators Handbook — Basic Course’, bearing a SUMLOCK ANITA Ltd / ROCKWELL International stamp, is a practical training manual for operating calculating machines.
It teaches keyboard techniques and methods for everyday commercial arithmetic, with a final section devoted to the 993/S model’s storage register.
The course begins with addition, subtraction, multiplication and division.
It emphasizes correct finger placement, rhythmic keystrokes and working without looking at the keyboard.
Operators learn how to position decimal points, handle fractions and recurring decimals, and reduce the number of keystrokes needed.
Multiplication is performed through repeated addition, while subtraction and division require specific keyboard procedures.
Further sections apply these techniques to business calculations, including:
- Discounts, price increases and successive percentage adjustments,
- Multiplication involving several factors and accumulation of products,
- Use of reciprocals to speed up repeated division,
- Pricing quantities expressed in pounds and ounces, yards and feet, gallons and pints, dozens, gross and tons,
- Metric conversions and prices quoted per hundred or thousand,
- Payroll calculations, overtime, deductions and cash denominations,
- Foreign-currency conversions and calculation of exchange rates.
The section on the 993/S storage register explains how a second register can retain totals while further calculations are performed.
Examples cover checking column totals, cross-casting tables, balancing debits and credits, accumulating rounded amounts, distributing sums proportionally and calculating percentage changes.
Throughout the handbook, accuracy and verification receive as much attention as speed.
Operators are encouraged to check subtraction by adding back, verify reciprocals by multiplication, repeat totals in reverse order and use ‘zero proof’ checks to confirm that results agree.
The document provides a detailed picture of the skills required for office calculation before modern electronic calculators automated many of these procedures.