#### How long will our oil last?

GIVEN that the Earth’s endowment of oil is about 3 trillion barrels AND GIVEN that current production is 85 million barrels a day IF world consumption remains at this level CALCULATE how many years we can continue to use oil. Further work GIVEN that the world population is 6.7 billion in 2010 IF world population … Continue reading

#### How far do I have to drive my car to use as much energy as it took to make it?

Many people forget that cars do not only burn fossil fuel, they need a lot to manufacture them. It would be useful to consider actually how much they need to manufacture considering many are talking about creating new electric cars to replace fossil ones. The following might help shed some light. GIVEN: A car manufacturer … Continue reading

#### Demonstrate and bury biochar as well

A nice little problem from friend and mentor Folke Gunther: Why demonstrate and say ‘Politicians, Do Something’? Says Folke: I suggest you demonstrate and then bury one kilo of biochar in your garden or wherever you can bury it If all the climate protesters buried a kilo of carbon each, that would at least make … Continue reading

#### Energy Slaves

Suppose we imagine all the energy we use that is not produced by our own muscles as energy slaves. This is what Buckmaster Fuller did. To understand his thinking better, visit this entertaining and informative comic strip by Stewart MacMillan. And then try the questions.

#### The price of carbon according to Swedish taxation levels

GIVEN: The Swedish government levies a CO2 tax on petrol at 2.62 kr per liter. GIVEN: A liter of petrol produces 2.315 kg of carbon dioxide. GIVEN: Carbon dioxide consists of three atoms: one carbon atom (12) and two atoms of oxygen (16 each) giving an atomic weight of 44. CALCULATE: The cost per kg … Continue reading

#### How much biochar do I need to bury actually?

Rob Hopkins – co-founder of Transition Towns – has been to Sweden and a publicity event was arranged to effectively remove carbon dioxide from the atmosphere by burying biochar. Here are some Maths Challenges around Biochar and emissions.

#### If the world were a village

There is a theory that we feel best when in smaller groups of about 200 people. Tribes in the jungle split when they get over 200. Corporations limit the size of units to 200. This maths problem asks if it is possible to organise the world in groups of 200 that send representatvies to groups … Continue reading

#### Outside work: get a feeling for a hectare and how much arable land there is.

If you have never tried it, this exercise, which can be done with schoolchildren, is quite enlightening, and something you can map out on the school playing field: One hectare can be easily understood if you are a small group and stake it out in a fairly large open space. Imagine you are … Continue reading

#### Bacteria growing in a bottle

This little exercise gives you a feel for exponential growth and what it means to resource availability. To get the basic idea try this. Given: a bacteria in a bottle of substrate fills the bottle in one hour, starting from one bacteria. The bacteria divides every minute. Calculate: how full is the bottle at 59 … Continue reading

#### Indigenuity

Indigenous = of a place Ingenius = very clever Indigenuity = living in a place in a clever, sustainable way Maths can help students makes sense of their world, to start to own it and to start to see ways to live more sustainably. Maths is an important component of indigenuity and teaching maths the … Continue reading