# How to Do Maths Without a Calculator - with Rob Eastaway

## Description

Knowing how to quickly estimate sizes and numbers is a useful everyday application of maths.

Buy Rob's book "Maths on the Back of an Envelope" now - https://geni.us/yaeUJw

How many cats are there in the world? What's the chance of winning the lottery twice? And just how long does it take to count to a million?

Join best-selling maths author Rob Eastaway as he takes an entertaining look at how to figure without a calculator. With amusing anecdotes, arithmetical challenges, and handy calculations tips, this is an engaging introduction to the essential skills of estimation.

Rob Eastaway is an author and speaker whose books include the bestselling "Why Do Buses Come In Threes?" - https://geni.us/QbyYF - and "Maths for Mums and Dads" - https://geni.us/IcRTPH. He is the Director of Maths Inspiration, a national programme of theatre-based lectures for teenagers. He regularly appears on BBC Radio 4's More or Less programme, and his puzzles can sometimes be heard on the Today programme. In 2016 he was awarded the Zeeman Medal for excellence in the communication of maths to the general public.

This talk and Q&A was filmed in the Ri on 18 October 2019.

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A very special thank you to our Patreon supporters who help make these videos happen, especially:

Andrew McGhee, Anna-Chiara Bellini, Dave Ostler, David Lindo, David Schick, Erik Shepherd, Greg Nagel, Jan Bannister, Joe Godenzi, John C. Vesey, Kellas Lowery, Lasse T. Stendan, Lester Su, Osian Gwyn Williams, Paul Brown, Radu Tizu, Rebecca Pan, Robert Hillier, Robert Reinecke and Roger Baker.

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The Ri is on Patreon: https://www.patreon.com/TheRoyalInstitution

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Our editorial policy: http://www.rigb.org/home/editorial-policy

Subscribe for the latest science videos: http://bit.ly/RiNewsletter

Product links on this page may be affiliate links which means it won't cost you any extra but we may earn a small commission if you decide to purchase through the link.

Buy Rob's book "Maths on the Back of an Envelope" now - https://geni.us/yaeUJw

How many cats are there in the world? What's the chance of winning the lottery twice? And just how long does it take to count to a million?

Join best-selling maths author Rob Eastaway as he takes an entertaining look at how to figure without a calculator. With amusing anecdotes, arithmetical challenges, and handy calculations tips, this is an engaging introduction to the essential skills of estimation.

Rob Eastaway is an author and speaker whose books include the bestselling "Why Do Buses Come In Threes?" - https://geni.us/QbyYF - and "Maths for Mums and Dads" - https://geni.us/IcRTPH. He is the Director of Maths Inspiration, a national programme of theatre-based lectures for teenagers. He regularly appears on BBC Radio 4's More or Less programme, and his puzzles can sometimes be heard on the Today programme. In 2016 he was awarded the Zeeman Medal for excellence in the communication of maths to the general public.

This talk and Q&A was filmed in the Ri on 18 October 2019.

---

A very special thank you to our Patreon supporters who help make these videos happen, especially:

Andrew McGhee, Anna-Chiara Bellini, Dave Ostler, David Lindo, David Schick, Erik Shepherd, Greg Nagel, Jan Bannister, Joe Godenzi, John C. Vesey, Kellas Lowery, Lasse T. Stendan, Lester Su, Osian Gwyn Williams, Paul Brown, Radu Tizu, Rebecca Pan, Robert Hillier, Robert Reinecke and Roger Baker.

---

The Ri is on Patreon: https://www.patreon.com/TheRoyalInstitution

and Twitter: http://twitter.com/ri_science

and Facebook: http://www.facebook.com/royalinstitution

and Tumblr: http://ri-science.tumblr.com/

Our editorial policy: http://www.rigb.org/home/editorial-policy

Subscribe for the latest science videos: http://bit.ly/RiNewsletter

Product links on this page may be affiliate links which means it won't cost you any extra but we may earn a small commission if you decide to purchase through the link.

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