The ancient Greeks wondered when “irrational” numbers can be approximated by fractions. By proving the longstanding Duffin-Schaeffer conjecture, two mathematicians have provided a complete answer. The ...

Text in an Excel cell may span several lines. For example, cells in a sheet listing employees may contain extended comments on each worker's performance. Excel controls the number of lines in such a ...

Use rounded values to estimate close the answer to a calculation. This is a useful non-calculator skill. Refresh your knowledge with these guides on rounding and significant figures. Rounding to ...