Uncovering the Mathematical Calculations Behind a Single Bite of Food

How many bowls of rice do you eat in a day?

How many cups of rice does your family cook for one meal? For a small household of four, how many kilograms of rice are needed in a month? Food is the first necessity of the people; since eating is such a matter of paramount importance, let us do some simple math.

One kilogram of rice can cook about 14 bowls of rice, roughly the amount of 7 rice-measuring cups. If you cook a little more than 2 cups of rice per meal, then one kilogram of rice will last about 3 meals.

If you subtract holidays when you eat out, subtract breakfasts that are not cooked at home, and subtract lunches eaten out, leaving only dinner at home, that is 21 meals at home per month, not counting packed lunches and not counting the extra dishes and extra rice during Chinese New Year. That means 7 kilograms of rice per month, and 84 kilograms of rice per year. In terms of 3-kilogram packaged rice, that is 28 bags of rice per year; multiply that by the unit price per bag, and that is the rice money that the "head of the household" - who bows for five pecks of rice and sells his liver to the boss - has to pay.

But to eat one kilogram of rice, how much paddy rice must be grown?

If we average the milling rate of white rice and brown rice, it is generally about 60 percent. In other words, to mill 60 kilograms of rice requires 100 kilograms of paddy rice (dry grain).

How much land is needed to grow 100 kilograms of paddy rice?

With my farming method, when the weather is favorable and heaven grants us a living, when the climate suits the growth of the rice, and when pests and diseases do not overrun the fields, one fen of land can yield about 420 kilograms of paddy rice (this year the newly rented land in Dongshan had a poor harvest, only 376 kilograms per fen). After conversion, one fen of land can mill 252 kilograms of rice [420 kilograms dry paddy x 0.6 milling rate], which can supply about the rice needs of 3 households for one year [252 kilograms / 84 kilograms per year].

How big is one fen of land? About 300 ping; converting again, one ping of land (the size of 2 tatami mats) can produce 0.84 kilograms of rice [252 kilograms rice / 300 ping], which can cook 11.76 bowls of rice [0.84 kilograms rice x 14 bowls of rice]. Subtracting the time for sowing and raising seedlings, rice takes about 120 days from transplanting to harvest. Converted into the farmer's daily "ping yield," that is 0.007 kilograms [0.84 kilograms rice / 120 days], which can cook 0.098 bowls of rice [0.007 kilograms x 14 bowls of rice]. If one bowl of rice is counted as 8 mouthfuls, how much effort does it take to eat one mouthful of rice? [1.275 days = 1 mouthful of rice / (0.098 bowls of rice x 8 mouthfuls)].

In other words, only when the farmer, the Earth God, and heaven above all work together, striving for 1.275 days on a double bed, is there one mouthful of rice to eat.

Perhaps this description is a bit of a strained analogy, but after such a simple calculation, will you cherish the bowl of rice in your hands a little more?