## Welcome to H3 Maths

Blog Support for Growing Mathematicians

## Archive for December, 2013

### H3 Mathematics on holiday

December29

Just a short note to inform followers that H3 Maths is on vacation for a few weeks – busy gathering more fun items to post!

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### Triangles…

December13

In this one of several posts on Triangles is a photo taken from an early French postcard, where children are using a triangle to play marbles;

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### Working with everyday numbers

December9

OK. Here is a sign at a bus stop in Singapore. Can you work out the different types of numbers – any primes; any squared numbers, odds and evens, etc.? It still amazes H3 how many students use numbers like these each day, but never actually study them. The mental gymnastics of number analysis is […]

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### Counting…Egyptian Style

December6

The early Egyptian records, from around 1800 BC, show a decimal system where objects represent the powers of ten (1,10,100, etc.). In this pictorial system there was no sign for zero or for decimals. Here is an example: and how it was used… Article source and more information on this remarkable mathematical culture here

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### I’ve grown used to your (math) face!

December1

This article, in the Financial Review, looks (pun intended) at how mathematical algorithms (Al Gore related??) are used for facial recognition. Wow – scary stuff for growing mathematicians?

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#### Post Support

The graph on the left (Coronavirus) is for a time period of 30 days, while the one on the right (SARS) is for 8 months! Very poor graphical comparison and hardly relevant, unless it is attempting to downplay the seriousness of the coronavirus?

10 x 9 x 8 + (7 + 6) x 5 x 4 x (3 + 2) x 1 = 2020

NCEA Level 2 Algebra Problem. Using the information given, the shaded area = 9, that is:
y(y-8) = 9 –> y.y – 8y – 9 =0
–> (y-9)(y+1) = 0, therefore y = 9 (can’t have a distance of – 1 for the other solution for y)
Using the top and bottom of the rectangle,
x = (y-8)(y+2) = (9-8)(9+2) = 11
but, the left side = (x-4) = 11-4 = 7, but rhs = y+? = 9+?, which is greater than the value of the opp. side??
[I think that the left had side was a mistake and should have read (x+4)?]