Look at what’s not there Zero is not a forgotten space: it informs you that there are no objects in the box. Now imagine removing the four units: they remain 20. Zero records that there are no loose units. Zero also has a story Brahmagupta registered calculation rules with zero at 628 in India. These include adding zero without changing the number and multiplying by zero obtaining zero. The history of zero involves contributions from different peoples. Your turn to investigate: Write 25 and 205. What does the zero say in the second number? Represent both on the class abacus. Discover the historical source on MacTutor, from the University of St Andrews.