Helen Chick

Mathematics educator, who believes in the awesomeness of maths and the power of great teaching

[Helen Chick @HelenChickMaths]

@golfballbfdi @HiHelloProd @Tantusar @ColinJChick Brilliant.

[Helen Chick @HelenChickMaths]

@aamtinc Why not include 9 as a starting number?

[Helen Chick @HelenChickMaths]

What is the mathematics that needs to change? (Agree that something needs to change … but is it maths, teaching maths, definition of being mathematical, what?) #merga45

[Helen Chick @HelenChickMaths]

Some complex ideas about restoring and restorying maths. A lot to do with racial/cultural issues, and “ways of knowing” and connections, but got me thinking about neurotypes and learning in environments that aren’t necessarily aligned with your culture/neurotype/etc. #merga45

[Helen Chick @HelenChickMaths]

Thought provocation has begun: ideas about embedding indigenous issues in maths. #MERGA45 (Also great to catch up with long-time and new colleagues!)

[Helen Chick @HelenChickMaths]

@nomad_penguin Eigeneigenvalue?
Eigenrhombitruncatedcuboctahedron?
Eigensushi?
Eigennonsequitur?

[Helen Chick @HelenChickMaths]

In fact, the lecture theatre shortest-path problem is a bit more complicated than in the previous tweet. The aerial view here shows the paths that surround the building (bordered in purple) with orange showing the entrances to the theatres.

[Helen Chick @HelenChickMaths]

A variation on taxicab geometry: what are the shortest routes from one lecture theatre to another? (No shortcuts through the centre, sorry!) #MAVCON

[Helen Chick @HelenChickMaths]

Amused — and appalled — by Paul Swan's real-world maths example of the hire car company that believed it was possible for one of their vehicles to have travelled 10000km in 41 hours (and charged for it). #MAVCON

[Allan Dougan @Allan_Dougan]

With @HelenChickMaths and @RachaelWSmith

[Helen Chick @HelenChickMaths]

@odgers_benjamin :-) (And I think there's another set.)

[Helen Chick @HelenChickMaths]

So here's a little problem that occurred to me last night: Are there three digits a, b, c such that abc, acb, bac, bca, cab, and cba are all prime? (It's a problem that is likely to have occurred to someone else before now, I suspect.)

[Helen Chick @HelenChickMaths]

@BarryKissane Does it make a difference if I said, specifically, that a, b and c don't have to be distinct?

[Helen Chick @HelenChickMaths]

@BarryKissane And cannot include 5.

[Helen Chick @HelenChickMaths]

@katherinequane Pt 4. What is interesting is to figure out why it works: why is it the odd half-multipliers that you need, and not the even ones? As a hint, what is 27 in base 2/binary?

[Helen Chick @HelenChickMaths]

Further on my explorations with the Russian Peasant method of multiplication: it's always fun trying to figure out how something works in a specific case and then how to generalise it to show it always works. #mathsreasoning

[Helen Chick @HelenChickMaths]

@katherinequane Pt 3. The ones with odd half-multipliers are 27x31, 13x62, 3x248 and 1x496, so you add 31+62+248+496, which gives 837 (which is the answer to 27x31).

[Helen Chick @HelenChickMaths]

@katherinequane Pt 2. So, if starting with 27x31; the halve-double then gives 13x62 (people seem to record the multiplication sign, but of course 27x31 ≠ 13x62), then 6x124 then 3x248 then 1x496.

[Helen Chick @HelenChickMaths]

@katherinequane Pt 1. Yes. Repeatedly halve the multiplier (rounding down to keep whole numbers) and double the multiplicand. Then add together those doubles which have an associated odd-valued halved-multiplier.

[Helen Chick @HelenChickMaths]

Just spent an interesting time working out the connections between Egyptian multiplication (which I knew about) and Russian Peasant multiplication (which I knew less about). There are some very nice connections with binary and place value understanding.