How many numbers could the Analytical Engine's store hold?

The Analytical Engine’s store was designed to hold 1,000 numbers.

In Charles Babbage’s architecture, the “store” was the machine’s memory. It would retain numbers, intermediate results, and variables needed during a calculation. The separate “mill” performed arithmetic operations, making the design broadly comparable to the memory and processing units of a modern computer.

Babbage’s planned store was intended to contain 1,000 decimal numbers, with different descriptions of the design specifying roughly 40 or 50 digits per number. The machine was never completed, so this capacity describes the proposed architecture rather than a working nineteenth-century computer. Even so, the design anticipated several modern concepts, including memory, conditional operations, loops, punched-card programming, and a distinct arithmetic unit.

The Analytical Engine grew out of Babbage’s work on the Difference Engine. The earlier machine was specialised for calculating tables by finite differences; the Analytical Engine was meant to be programmable and general-purpose. Ada Lovelace’s celebrated 1843 notes explained how such a machine might manipulate symbols and included an algorithm for Bernoulli numbers.

The smaller figures in the options confuse the store with other capacities or simplified descriptions. The canonical figure for the planned Analytical Engine memory is 1,000 numbers.