- Books Name
- CBSE Class 6 Mathematics Book

- Publication
- Param Publication

- Course
- CBSE Class 6

- Subject
- Mathmatics

**Introduction**

The branch of mathematics in which we studied numbers is arithmetic.

In Arithmetic, numerals 1, 2, 3, 4 , -------- etc. and four fundamental operations : addition , subtraction, multiplication and division are used to deal with various problems. In Algebra, in addition to numerals, we use letters such as x, y, z in various situations to solve the problems.

**Matchstick Patterns**

Ram and Sarita are making patterns with matchsticks. They decide to make simple patterns of the letters of the English alphabet. Ram takes two matchsticks and forms the letter L as shown in Fig (1). Then Sarita also picks two sticks, forms another letter L and puts it next to the one made by Ram Fig (2). Then Ram adds one more L and this goes on as shown by the dots in Fig (3).

Number of matchsticks required = 2 × number of Ls. For convenience, let us write the letter n for the number of Ls. Thus, n can be any natural number 1, 2, 3, 4, 5, .... We then write, Number of matchsticks required = 2 × n. Instead of writing 2 × n, we write 2n. Note that 2n is same as 2 × n.