The ability to round a number to a number of decimal places or to a number of significant figures means that answers can be written to an agreed degree of accuracy. Watch the video to learn how ...

The circumference of a circle is the distance around the circle. It is another name for the perimeter of a circle. The circumference of a circle is calculated using the formula: \(\text{circumference} ...

So you have a circle. What is the area of that circle? Surely everyone remembers that the area of a circle is: Where Pi (π) is of course the number and r is the radius of the circle. Where does this ...

Now for the important part. Today, as you may know, is Pi Day. Why today? Because it’s March 14—yes, 3/14—and 3.14 is the value of pi to two decimals. Of course, the actual number continues to an ...

Scientific American presents Math Dude by Quick & Dirty Tips. Scientific American and Quick & Dirty Tips are both Macmillan companies. Throughout history, circles have symbolized many things: unity, ...