Page 189 - ICSE Math 4

Example 4: Find the next number of the following pa erns and write the rule.
(a) 95, 90, 85, 80, 75, ___

(b) 480, 240, 120, 60, 30, ___

Solu on: (a) In the given pa ern of numbers, we can see that the numbers are
arranged in a decreasing order. The rule followed in this pa ern is to
start at 95 and subtract 5 each me from the previous number.

95 90 85 80 75 _____

–5 –5 –5 –5 –5

Therefore, the required number in the given pa ern is 75 – 5 = 70.

(b) In the given pa ern of numbers, the rule followed is to start at 480 and
half the number or divide the previous number by 2 to obtain the next
number.

480 240 120 60 30 _____

2 2 2 2 2
Therefore, the required number in

the given pa ern is 30 ÷ 2 = 15.
Growing Shape Pattern Mental Maths
Fill in the blanks by observing the
In a growing shape pa ern, the pa ern grows given number patterns.
due to the addi on of a new shape or a unit to (a) 73, 76, 79, ____ , 85, ____ , ____
the already exis ng shape or unit. Look at the (b) 45, ____ , 35 , ____ , 30, 25, 20
shape pa ern given below.

1 2 1 2 2 1 2 2 2
unit 1 unit 2 unit 3

Observe that the pa ern rule here is to add a new shape (triangle) to the already exis ng
unit of shapes. It can also be seen as 1 2; 1 2 2; 1 2 2 2 and so on.
Example 5: Complete the given shape pa erns by iden fying the pa ern rule.

(a)
_____________________

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