Page 179 - New Medley 5 Semester 2

Patterns with Number

Observe the following patterns made with matchsticks:

2 matchsticks 4 matchsticks 6 matchsticks

How many matchsticks will be required to make the 11th and 25th patterns?

We see the number of matchsticks in the given pattern as: 2, 4, 6, ... i.e.,
1 × 2, 2 × 2, 3 × 2, ...

i.e., Number of matchsticks = Number of ‘L’ shapes × 2

[This is the rule for making pattern.]

 Number of matchsticks in 11th pattern = 11 × 2 = 22

and number of matchsticks in 25th pattern = 25 × 2 = 50

Thus, we can calculate the required matchsticks by finding the rule involved

in the pattern.

Some Other Number Patterns

Triangular Numbers

...

1 3 6 10 15 ...

In the above pattern, triangular numbers are

1, 3, 6, 10, 15, ...

It can be expressed as:

1 × 2
1st term = 1 = 1 =
2

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