When you return to yourquarters, right away you should close your eyes and clearly envision the numberof individual places in the [sangha] hall; the number of monks in theindividual quarters of retired minor officers, retired senior officers, and thelike; how many individual monks there are in the infirmary, geriatric quarters,temporary quarters, and so on; the number of wandering monks registered in theguest quarters; and the number of people in subtemples. After carefullycalculating in this way, if you have the slightest uncertainty, ask the hallmanager in question, or the quarters prefect, quarters chief, or quarters headseat of the various quarters and eliminate your doubts.

Now carefullycalculate: for every grain of rice to be eaten, one grain must be supplied. Ifa single grain of rice is divided, then you will have two half-grains of rice.Three tenths, four tenths; one half, two halves. If you supply two half-grainsof rice, you will make a single whole grain. [You must be able to see clearly how much of a surplus will be created if you add one unit of rice, or whether there will be enough if you take away one unit].

From: Tenzo Kyokun - Instructions for the Cook by Eihei Dogen - Translated by Griffith Foulk [with portion from Uchiyama]