Memorizing Multiplication Tables
| Field | Mathematics |
| Went Obsolete | Varies |
| Made Obsolete By | Cheap electronic calculators |
| Knowledge Assumed | none |
Understanding the world we live in is now obsolete? Being able to do basic math in your head makes learning most of the sciences easier or in some cases even possable. Also, you would look kinda silly pulling out a calculator to figure out how many quarters you need to give the cashier 75 cents