slipstick
/ˈslɪpˌstɪk/
noun
- A slide rule, a simple mechanical device used for calculating numbers, especially before electronic calculators became common.
- The teacher showed the class an old slipstick and explained how it worked.
- My grandfather used a slipstick to solve math problems when he was an engineer.
- Before computers, every scientist carried a slipstick in their pocket.