Why error loggers love 21st Night

Error logs are based around two simple ideas:

  1. It’s helpful to analyze problems you got wrong, so you know how to solve the next, similar problem
  2. It’s easy to forget how to do old, difficult problems unless you test yourself on them periodically

21st Night helps with both of these in big ways.

First of all, as you’d expect, you can put any problem into a 21st Night error log. Take a screenshot, take a picture with your phone, copy-paste, type up an equation in the rich text editor: however you want to do it, it just works.

Screenshotted straight from a practice test!

Because 21st Night brings up questions to review based around a spaced repetition algorithm, it also makes sure you don’t forget your old, tough questions. It also uses a streak reward system, to keep you motivated to keep reviewing!

Finally, to help you with your analysis, 21st Night has a detailed analytics system, making it easy to know what you’ve done and what to do next.

Don’t want to start from scratch? No problem! You can upload your old questions in a csv, including any images you might need.

So why not try a free trial of 21st Night? No credit card required!