## Welcome to H3 Maths

Blog Support for Growing Mathematicians

## Posts tagged with graphs

### Double Stem and Leaf

September10

Double stem and leaf plots are used to compare two distributions side-by-side. This type of double stem and leaf plot contains three columns, each separated by a vertical line. The center column contains the stems. Example  – Making a double stem and leaf plot for the data gathered by students doing traffic counts at different times […]

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### Grab a Graph

September9

A graph is a visual story for mathematicians. You choose the one that best illustrates the story you are telling with the data you have collected. For example, this stem and leaf is a cool way to show the exam scores for a class. Turn your computer (or your head) sideways (to the left) and […]

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### Earnings and Inflation

March25

A senior maths class I taught recently were looking at Inflation and how this factor affects compound interest. For example, you might invest \$100 dollars at 10% compounding interest over 10 years. How much would your total be? Now, you might expect a healthy profit but your new found wealth might be severely influenced by […]

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### Graph Analysis – Patterns or not?

March17

Many companies exist to analyse trends in the property market. This graph comes from a New Zealand company who provide statistical reports for houses, apartments and lots (sections) for different locations in New Zealand (in other words, they make a living from Mathematics!). This information is really valuable for many developers and private buyers and […]

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### Arctic Ice Trends – Test Your Extrapolation Skills

February28

We often use data patterns in Mathematics to predict future data. This can be done in a variety of ways. One simple way is to take the known data, graph it, and then extrapolate the data – that is, extend it into the future and read off the likely values that might occur. For example, […]

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#### Post Support

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)?]