Page 131 - ICSE Math 6

literals. As literals are also numbers, therefore all the rules for addition,
subtraction, multiplication and division of integers and fractions hold Try These
true for them. 1. Write any five variables.
2. Is 7 + 3 a variable or constant?
Matchstick Patterns

1. Sameer decides to make patterns of squares using matchsticks as shown below:

…

The table shows the number of matchsticks required to make above patterns of squares.

Number of squares 1 2 3 4 5 6 7 ... ...

Number of matchsticks used 4 7 10 13 16 19 22 ... ...

We observe that the number of matchsticks required = 3 (Number of squares) + 1
= 3 × n + 1 = 3n + 1
2. Sarita and Savera were making patterns of triangles using matchsticks as shown below:

…

The table shows the number of matchsticks required to make above patterns of triangles.

Number of triangles 1 2 3 4 5 … …

Number of matchsticks 3 6 9 12 15 … …

We observe that the number of matchsticks required = 3 (Number of triangles) = 3n

Example 1: Find the rule which gives the number of matchsticks required to make the pattern by
putting the following letters next to one another in a sequence. Use a variable to write
the rule.

(a) A pattern of letter S as (b) A pattern of letter A as

Solution: (a) The rule for pattern of letter S is given in the following table.

…

Number of letters ‘S’ 1 2 3 4 5 … n
Number of matchsticks 5 10 15 20 25 … 5n

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