Counting Large Numbers of Events in Small Registers It is possible to use a small counter to keep approximate counts of large numbers. The resulting expected error can be rather precisely controlled. An example is given in which 8-bit counters (bytes) are used to keep track of as many as 130,000 events with a relative error which is substantially independent of the number n of events. This relative error can be expected to be 24 percent or less 95 percent of the time (i.e.o = n/8). The techniques could be used to advantage in multichannel counting hardware or software used for the monitoring of experiments or processes. CACM October, 1978 Morris, R. Counting 5.11 CA781005 DH January 29, 1979 5:52 PM 3056 5 3056 3056 5 3056 3056 5 3056