MathsClass

Conic sections – Dandelin spheres 12 Jan 2013 · via Nordin Zuber

Visualisation of conic sections made by shining light on a sphere – and the associated sphere which would make up a Dandelin pair.

Conic sections – Skiagraphs 12 Jan 2013 · via Nordin Zuber

Conic sections produced by shadows. Another in the collection of animations made by the elica team.

Conic sections – Darkness 12 Jan 2013 · via Nordin Zuber

A short 30 second clip showing conic sections resulting from a torch shined on a soccer ball.

Calculations involving exponential growth: world population 11 Jan 2013

Recently the world's population passed seven billion and it continues to grow by 200,000 people every day. Listen to some reasons why our population is growing at such a rate, and the strain this will put on resources such as food and water. This clip provides context for calculations involving exponential growth.

Calculating ratios and percentage: gold price 11 Jan 2013

Gold is a very precious metal. Listen to reporter Natasha Thiele explain how gold became so valuable and why the price of gold fluctuates. Find out how the ratio of dollar value per unit weight is used to calculate the value of an amount of gold. This clip provides a context to calculate ratios and percentage.

Calculating percentage and simple interest: Banking 11 Jan 2013

Most of us use banks to keep our money safe. We put our money in, can access it at any time and earn interest. So how do the banks make such enormous profits? Where does that money come from? Listen to Nathan Bazley explain how the banks use your money and make a profit. This clip provides a context for percentage, simple interest and decimal multiplication.

Calculating area: locust plagues 11 Jan 2013

How many locusts in a plague? Find out just how big the threat of locusts can be and how farmers try to prevent the plagues from getting out of control. This clip provides context for a combination of area, area units and rate problems.