## Welcome to H3 Maths

Blog Support for Growing Mathematicians

## Archive for May, 2012

### Go West Young Man!

May31

Yes, the cry of the early USA settlers was “Go West Young Man”. This exciting period of exploration led to large numbers of people travelling out to Oregon in the far west (read some interesting Trail Facts here). They faced incredible difficulties and many challenges, not only on the journey but also in settling into […]

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### Information is Beautiful

May30

Back in 2010, the Information is Beautiful website calculated there were 74 million more women on social networks than men. We’ve had a fresh look at the data. In the age of Facebook, Pinterest and Instagram, do the girls still rule? Here is a composite graphic we made up from the site:

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### Coincidences

May30

“It is a small world, isn’t it? You are on holiday in the Pyrenees. You write a postcard to a friend at home and set off to post it. Then who should you meet but that same friend coming up the street. This not only saves you the cost of a stamp but it also provides […]

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### Solving another Volume problem…

May28
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### Volume Example

May28

Here is a typical volume problem when working with a cylinder. Remember that the solution is to find the end area (circle) and then multiply that by the height (or length) of the cylinder:

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### For Volumes we first need areas!

May28

Have a close look at this following aerial picture, taken over the city of Brisbane, Australia.  The fuel tanks are cylinders and you can clearly see that the tops are shaped like circles. So, we would use the area of a circle formula to find the area(s) of the top of each tank. To find […]

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### Circle Area

May28

As we saw in the last posting, the area of a circle is given by; So, to find the area of a circle we multiply pi (3.1415…) x the radius squared. Our answer will be something squared. Another way to think of area is how many square tiles would fit the shape, etc. In the […]

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### Finding Areas – a Quick Summary

May27

Here are the most common areas which students are required to calculate. Note that areas are ALWAYS expressed as something squared (such as squared metres):

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### News just in…16yo solves 300 year old Maths riddle

May27

Click on the following heading for more…

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### How high is a stack of \$100 bills in a \$billion??

May27

This caught my attention in one of the dailies; “Imagine a \$100 bill,” I began. “Now imagine a wad of them from the bank wrapped up tight. There’s a hundred of them. That’s \$10,000. Now imagine stacking wads of \$100 bills one on top of another… “A hundred wads and you have a metre. That’s […]

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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)?]