Circulatory System Worksheet Answer Key. A worksheet, in the term’s original meaning, can be a sheet of paper on which one performs work. It’s a printed page that a child completes with a writing instrument. No additional materials are needed. It’s”a sheet of paper on which workouts, working time, special instructions, etc. are listed. A bit or scrap of paper on which problems, ideas, or so on, are set down in tentative form.” In education, a worksheet could have questions for pupils and areas to document responses. In accounting, a worksheet is, or was, a sheet of ruled paper with columns and rows on which an accountant could record data or perform calculations.