Timeline for What's a great christmas present for someone with a PhD in Mathematics?
Current License: CC BY-SA 4.0
14 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Dec 14, 2020 at 17:21 | comment | added | Rita Geraghty | Soroban acabus is taught in all schools in Asia and it makes kids insanely fast mental calculator. youtube.com/watch?v=5gWzNjYx1bY | |
| Dec 14, 2020 at 16:58 | comment | added | Rita Geraghty | This is the first model of soroban abacus that I bought. amazon.co.uk/gp/product/B07YZ59KR1/… Afterwards, I bought another soroban with two colours. amazon.co.uk/gp/product/B07LFYV4LJ/… | |
| Dec 14, 2020 at 16:55 | comment | added | Rita Geraghty | @MattF. I also bought this book on suanpan acabus showing how to do multiplications & divisions, squares, cubes, roots, etc. amazon.co.uk/gp/product/1460958810/… | |
| Dec 14, 2020 at 16:53 | comment | added | Rita Geraghty | @MattF. Sorry for my spelling mistake. It is suan pan or suanpan, a Chinese abacus. It is easier to use than soroban abacus which has two beads less on each column. I bought same model at this Amazon store. amazon.co.uk/gp/product/B07ZMQCS52/… | |
| Dec 14, 2020 at 7:57 | comment | added | Toby Bartels | @KingLogic : But Rita mentioned both Soroban and Sudoban as separate kinds. | |
| Dec 14, 2020 at 2:22 | comment | added | KingLogic | @MattF. probably soroban abacus (Japanese abacus) | |
| Dec 13, 2020 at 2:42 | comment | added | user44143 | @RitaGeraghty, what is a Sudoban abacus? (There are no google hits for that phrase other than your comment.) Meanwhile, abacus gifts sound more pleasing than a slide rule. | |
| Dec 12, 2020 at 19:00 | comment | added | Deane Yang | Oooh. Great idea. I used to drool over slide rule catalogs. | |
| Dec 12, 2020 at 18:47 | comment | added | Piotr Hajlasz | I have a vintage slider rule after my grandfather who was an engineer. Unfortunately, I do not know how to use it, but I promised myself I will learn it. | |
| Dec 12, 2020 at 16:46 | comment | added | Rita Geraghty | @NikWeaver I recently bought two slide rules and now I'm awaiting a third one in the post. A month before buying my first slide rule, I also got myself a few Soroban abacuses and a Sudoban abacus, as I was curious about them. I was intrigued by some Asians who worked natural logarithms on acabuses. And exponents and roots too. So I bought them. I am struggling to get the hang of them. Have you ever used them? youtube.com/watch?v=q62hQVfVGxU | |
| Dec 12, 2020 at 16:19 | comment | added | Nik Weaver | I remember realizing that slide rules use a log scale to convert multiplication into addition. Such a nice application of an abstract fact for a concrete, practical purpose. | |
| Dec 12, 2020 at 16:15 | review | First posts | |||
| Dec 12, 2020 at 16:19 | |||||
| S Dec 12, 2020 at 16:11 | history | answered | Rita Geraghty | CC BY-SA 4.0 | |
| S Dec 12, 2020 at 16:11 | history | made wiki | Post Made Community Wiki by Rita Geraghty |