Colleagues meet constantly to compare notes ... has an Erdös number of 2. Andrew Wiles has an Erdös number no greater than 3. One can look at mathematical collaborations as a graph—an array ...

It shows that if you buy 0 litres, it will cost £0. This graph shows the cost of hiring a ladder for various numbers of days. Using the points (1, 10) and (9, 34), the gradient \(= \frac{change~up}{ ...

It's essentially a calculation canvas you can use to work out equations and draw graphs ... numbers that need adding up—as soon as you draw a line under them, you'll get the total. Math Notes ...