From the same time period come the manually operated and far less complex Napier's Bones. Still pretty neat, and more likely what the 'average' person needing a

From the same time period come the manually operated and far less complex Napier's Bones. Still pretty neat, and more likely what the 'average' person needing a calculating device would have used. https://en.m.wikipedia.org/wiki/Napier%27s_bones https://en.m.wikipedia.org/wiki/Napier%27s_bones