You have studied various types of numbers such as natural numbers, whole numbers, integers and rational numbers.You have also studied a number of interesting properties about them. In grade 6, we explored finding factors and multiples and the relationships among them. In this chapter, we will explore numbers in more detail. These ideas help in justifying tests of divisibility.
In grade 6, you learnt how to check divisibility by the following divisors: 10, 5, 2, 3, 6, 4, 8, 9, 11. You would have found the tests easy to do, but you may have wondered at the same time why they work. Now, in this chapter, we shall go into the “why” aspect of the above.