Estimation and Approximation— Not Synonyms
Lucien T. Hall · Mathematics Teacher Learning and Teaching PK-12 · 1984
An estimation is usually considered to be an educated guess. The more experienced a person is at a given estimating task, the better one estimates. To illustrate, suppose we think of a salesperson who has sold carpet by the square yard for twenty years. Because a salesperson has actually measured so many rooms, he or she is usually very good at estimating the number of square yards of carpet needed to cover a given room.