Natural Learning : Maths of the fishpond

I bought some new plants for my fishpond and they are not looking happy. It turns out that because I removed a rampantly growing plant this has upset the balance of my pond and the increase in algae (observable by the green water) is robbing the new plants of nutrients.

So I have to treat my pond, now, I need maths to do that. I have to work out how many litres of water are in the pond.  My pond is squarish in shape - I just used maths - if it isn't square then it is a rectangle.


I need to measure from side to side which = 72cm
I need to measure from front to back which = 63 cm and
I need to measure the depth of my pond which = 33cm.
Now I multiply 72 x 63 x 33 = 149688 cubic centimetres. To convert that into litres I divide by 1000 or multiply by 1.000 and I have 149.688 litres of water in my fish pond.

The 'Pond Clean' needs to be added at 10ml per 250 litres, so I will need to work out how much of the 'Pond Clean' that I need for my pond.

The link below provides an easy to understand explanation of working out volume.

Calculating Volume

An interesting exercise taken from :  Learning Activities from the History of Mathematics

Ancient Babylonian and Egyptian mathematician - scribes were excellent record keepers. One of their tasks was to determine the quantities of bricks and building stones needed for the large structures built in their societies. Modern archaeologists have uncovered numerous lists and records of Babylonian and Egyptian building materials. One of the most impressive structures of the ancient Eastern world was the ziggurat, or step-pyramid. These "towers to heaven" were constructed from rectangular prisms stacked one upon another. Each prism was a pile of solid blocks. The ancients built their ziggurats by piling up blocks. These builders also knew how to compute the volume of a rectangular prism whose length was b, width was w, and height was h:

V = b x h x w 

A ziggurat