## Welcome to H3 Maths

Blog Support for Growing Mathematicians

## Posts tagged with waldomaths

### Video tutorials from Waldomaths

August6

Many students have found the video tutorials provided by Ron Barrow of Waldomaths quite helpful. For example, many of my Yr 8-10 students have greatly improved their understanding of Gradients of Straight Lines by watching this explanation;

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### Gradients of Straight Lines revisited

July23

You are probably already familiar with the concept that the gradient or slope of a straight line is how much it rises over a given horizontal length – that is, the rise divided by the run. This video clip from Waldomaths is a very good explanation of gradients, and uses several examples: The gradient of […]

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### Enlargement (or Dilation) with a great app

March11

There is a good app from waldomathsÂ (Java required) to see what happens when we have scale factors that are positive, zero and negative. For example, what would the image of a shape look like if it is enlarged by a scale factor of -3 rather than +3 ??               […]

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#### Post Support

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)?]