Manufacturer: Exactus | Made in England
Era: 1950s Mid-Century Vintage
Currency Standard: Pre-Decimal British Currency (£ s d – Pounds, Shillings & Pence)
Up for sale is an authentic 1950s Exactus 'Mini-Add' mechanical pocket calculator, engineered and manufactured in England.
This ingenious mid-century device was designed for shopkeepers, accountants, and everyday shoppers to quickly total accounts in pre-decimal British currency (£ s d) prior to the 1971 decimalisation system.
It operates mechanically by using a stylus tool to slide the internal metal numeric tracks up or down. A key feature of the Exactus design is its flip-over cover plate mechanism, which alters the register guides to switch easily between Addition and Subtraction modes.
Pre-Decimal Currency System: Calculates Pounds (£), Shillings (s), and Pence (d).
High Capacity: Handles calculations up to £99,999 19s 11d.
Dual Operation: Reversible flap flips over to clear guides for both Addition and Subtraction operations.
Compact Mechanical Design: Pocket-sized, durable metal slide construction with no batteries or electronic components required.
Mechanical: Metal slide mechanism operates smoothly across all columns.
Cosmetic: Very good condition, clean original face text, and light age-appropriate surface wear (see high-resolution photos for full aesthetic details).
Stylus: Included (as pictured).
Vintage Calculator & Early Computing Collectors
Pre-Decimal British History & Office Antique Enthusiasts
Mid-Century Design, Curio & Gadget Collectors
Film, Television & Theatre Period Prop Master Departments
Brand: Exactus
Model: Mini-Add (Mini Add)
Country/Region of Manufacture: United Kingdom (Made in England)
Era: 1950s (Pre-Decimalisation / Mid-Century)
Type: Mechanical Slide Pocket Calculator / Adding Machine
Currency Format: Pre-Decimal £ s d (Pounds, Shillings, Pence)
Max Capacity: £99,999 19s 11d
Material: Metal Slides & Housing / Reversible Cover Flap
Condition: Pre-Owned Vintage (Good Cosmetic & Mechanical Condition)