Originally, I intended to write a post today about whether it’s worth growing certain sorts of fruit and vegetables and how you should work it out. I was pondering this as I picked raspberries in the sunshine this morning. To me, raspberries are certainly worth growing – I love them and they take relatively little maintenance. However, because we have grown them for so long, I’m not entirely sure how much they cost to buy in a supermarket. My perception is that they are costly to buy and so I probably wouldn’t eat many of them if I didn’t grow them.
So, on my return from the garden, I decided to find out exactly how much raspberries do cost. I was right – they aren’t cheap ( I guess it’s related to the very careful handling that is required), but what I didn’t realise is that they distort numbers. Did you know this? The mathematics of berries is different to the mathematics we normally use. I am reminded of Douglas Adams’ bistromathics… I think I have discovered berriomathics.
Don’t believe me? Well, take a look at this:
The easiest way to compare prices should be to look at the price per kilo… and that’s what I did to begin with… until I realised that, apart from all but the first one in this screen shot, none of the £/kg values correspond the the item price. For example, the organic raspberries cost £2.50 for 125g. Last time I looked, 125 went into 1000 eight times, so the price per kilo should be 8 × £2.50 = £20. But look at what the figure on the web page is: £16.67! Quite a difference. The next one down is even more wrong: 1000/225 = 4.44, so the price per kilo should be 4.44 × 2 = £8.88, but it’s quoted as £13.34. Similarly, both of the £/kg prices for the blueberries are wrong if we base them on the unit price.
Now, I have a real issue with this sort of error… it is misleading to customers, particularly anyone in a hurry who does not have time to do their own sums, but also it’s downright careless, displaying complete contempt for numeracy.
Anyway, my conclusion is that the investment in a few raspberry canes six years ago has certainly paid off. Plus, berries are supposed to improve your memory, so they should help me remember how to calculate the best bargains next time I go shopping!