Page 2 - WS1.1

1 + 3 + 5 + 7 = 16

1 + 3 + 5 + 7 + 9 = 25
Observe the pa ern given below. Why does this happen?
7. What happens when you add up pairs of consecu ve triangular
numbers?
8. Find the missing number in the pa ern: 8, 16, __, 64, 128.

9. Iden fy the rule in the pa ern: 1, 8, 27, 64, __, __.
10. What is the formula for the pa ern of this sequence and write the next
number in the sequence?
7, 14, 21, 28, 35, 42, 49, ____

ANSWER:
1. b) Triangular numbers
2. A sequence of numbers in which each number (star ng from the third

term) is the sum of the two preceding ones. For example: 1, 2, 3, 5, 8,
13, 21….
3. A sequence of numbers in which each number is obtained by
mul plying by itself.
For example: 4,9,16,25, 36……

4. A sequence of numbers in which each number is obtained by
mul plying a number by the same number three mes. For example:
8, 27, 64, 125……
5. Coun ng numbers, odd numbers, even numbers, Triangular numbers,
Squares.
2
6. The sum of first n odd natural numbers is n . The sum of successive
odd numbers star ng from 1 is square numbers.

7. When we add up pairs of consecu ve triangular numbers, we get the
sequence of square numbers.
8. 32
9. 125, 216
10. 7n, 56