In the sentence,
Such software is referred to as threaded, or multi-threaded. The software adding, say, a column of four place numbers could drive the job into four threads: Adding the 1s-place numbers, the 2s-place numbers, the 3s-place numbers, and the 4s-place numbers. Each of those subtasks is directed to a different core.
It is from "How Computer Works" can be downloaded from http://epdf.pub/how-computers-work-9th-edition.html
What is the meaning of "a column of four place numbers"? And/or what is the meaning of "adding a column of four place numbers"?
I guess four place numbers are like "1234". Right?
Thank you in advance.