Uploaded February 2020 | Updated September 2026, 2 weeks ago

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Do check out Jane Street's Real Numbers:
janestreet.com/real-numbers

Here is a scan of all the working out:
dropbox.com/s/e0gg5bc891kny3t/pencil-maths.pdf?dl=0

We have a full break down of the working out for teachers:
think-maths.co.uk/standupmaths-videos?yt-pencils#pencils
There are Think Maths free resources for teachers for most of my videos!
think-maths.co.uk/standupmaths-videos

CAMERA ISSUE
Yes we did lose the video file from the GoPro filming the working out! So I had to recreate it using a scan of the pages. Which raises a question: which do you prefer? A GoPro pointing at the notes (like from 11:31 onwards) or an animated scan (like up until 11:05)? Let me know your thoughts in the comments!

CORRECTIONS
- Nothing yet! Let me know if you spot anything.

Thanks as always for Jane Street being my principal sponsor.
janestreet.com

Thanks to my Patreon supporters who help make these videos possible. Here is a random subset:

Andrew Wieland
Alan McNea
Richard Dickins
Tracy Parry
Aimee Arost
Henry Gustafson

Support my channel and I can make more maths videos:
patreon.com/standupmaths

Filming and editing by Trunkman Productions
Audio by Peter Doggart
Music by Howard Carter
Design by Simon Wright


MATT PARKER: Stand-up Mathematician
Website: standupmaths.com
Maths book: wwwh.umble-pi.com
Nerdy maths toys: mathsgear.co.uk