Well, WitCH 2, WitCH 3 and Tweel’s Mathematical Puzzle are still there to ponder. A reminder, it’s up to you, Dear Readers, to identify the crap. There’s so much crap, however, and so little time. So, it’s onwards and downwards we go.

Our new WitCH, courtesy ofÂ *New Century Mathematics*, *Year 10*Â (2014),Â is inspired by the Evil Mathologer‘s latest video. The video and the accompanying articles took the Evil Mathologer (and his evil sidekick)Â *hundreds* of hours to complete. By comparison, one can ponder how many minutes were spent on the following diagram:

OK, Dear Readers, time to get to work. Grab yourself a coffee and see if you can itemise all that is wrong with the above.

## Update

Well done, craphunters. Here’s a summary, with a couple craps not raised in the comments below:

- In the ratioÂ a/b, the nature of a and bÂ is left unspecified.
- The disconnected bubbles within the diagram misleadingly suggest the existence of other, unspecified real numbers.
- The rational bubbles overlap, since any integer can also be represented as a terminating decimal and as a recurring decimal. For example, 1 = 1.0 = 0.999… (See here andÂ here and hereÂ for semi-standard definitions.) Similarly, any terminating decimal can also be represented as a recurring decimal.
- A percentage need not be terminating, or even rational. For example, Ď€% is a perfectly fine percentage.
- Whatever “surd” means, the listed examples suggest way too restrictive a definition. Even if surd is intended to refer to “all rooty things”, this will not include all algebraic numbers, which is what is required here.
- The expression â€śhave no pattern and are non-recurringâ€ť is largely meaningless. To the extent it is meaningful it should be attached to all irrational numbers, not just transcendentals.
- The decimal examples of transcendentals are meaningless.