 So the normal size of an apple it's roughly a sphere, and I guess it's what 10 centimeters So I need to figure out how many of those are going to fit in my truck Okay, so how big is a truck a? Truck is Meters big I guess this would be I used for my chocolate example. I use four meters. Let's use that four meters and it might be maybe two meters high about a person's height and And Maybe two meters wide as well And so now I just do a volume calculation. So the volume of my truck is going to be four meters by two meters How wide shall we make it? approximately Two meters now if I get these numbers wrong then I'm going to get the wrong answer I'm not going to be too worried about that because what I'm just trying to see is whether it's significant or not If I get a really tiny fraction Then it doesn't matter if I get it wrong by a factor of two It's still going to be tiny on the other hand if it's comparable if it's maybe half of the cost of an apple Then I'm going to go. Oh, this is really important. We should be far more careful about these numbers Okay, so that's my volume of a truck So that's going to be four times two times two is 16 cubic meters my volume of my apple is Thousand cubic centimeters now. What's the cubic centimeter in cubic meters? I could take this previous thing and I could multiply by One meter divided by a hundred centimeters That would cancel one of those centimeters And leave me with a meter and I could do that again and again and I could end up with the completely equivalent answer of a Thousandth of a cubic meter, which is ten times ten times ten divided by a hundred divided by a hundred divided by a hundred So once again, we've made the step of making a very simple version of the formula for volume of an apple I just said it's about ten centimeters and so I assumed it was a ten centimeter cube And of course you might decide that an apple is more like a ten centimeter sphere But again, that's only going to change the numbers by a little bit And we are only trying to see whether the price from the transport of an apple is significant or not Okay, so what we can see is we've got 16 cubic meters of truck and a thousandth of a cubic meter for an apple So the number of apples that we can transport is about 16,000 and the price is about six hundred dollars And so the price per unit apple comes out to about four cents per apple if we round up So what that tells us is in fact that the truck transport from the market to the supermarket is a fairly small Fraction of an apple's price and if I was to adjust these numbers I might find it more accurately But they don't have to worry too much. It's not like it's all coming from that truck