Page 90 - NUMINO Challenge_C1
P. 90
Basic Concepts Group Sequences
A group sequence is a sequence that is made up of number groups that
follow the same pattern.
(1, 2, 3), (3, 4, 5), (5, 6, 7), (7, 8, 9),
For some sequences, it is easier to find the pattern after you group the
numbers.
1, 1, 2, 1, 2, 3, 1, 2, 3, 4, (1), (1, 2), (1, 2, 3), (1, 2, 3, 4,),
Index of Term
An index of term indicates the order in which the term appears in a sequence.
For example, consider the sequence: 2, 4, 6, 8, 10,
The 3rd term 6 has an index of 3. The index of 6 is 3.
The 4th term 8 has an index of 4. The index of 8 is 4.
Example The sequence below follows a certain pattern. Find the 50th term.
1, 2, 3, 2, 3, 4, 3, 4, 5, 4, 5, 6,
Class Notes
Group the sequence by putting three numbers in each group.
(1, 2, 3), (2, 3, 4), (3, 4, 5), (4, 5, 6),
As each group contains three numbers, the multiple of 3 that is closest to but
smaller than 50 is 3 3 33 .
16 terms .
So the 50th term of this sequence is the second number of group
Since the first number of each group starts from 1 and increases by 1, the first number
of group 17 is . Since the numbers of each group increase by 1 from the first
number, the second number of group 17 is .
Therefore, the 50th term is .
Try It Again Find the 20th term of the sequence.
1, 2, 3, 3, 4, 5, 5, 6, 7,
87Rules and Numbers
A group sequence is a sequence that is made up of number groups that
follow the same pattern.
(1, 2, 3), (3, 4, 5), (5, 6, 7), (7, 8, 9),
For some sequences, it is easier to find the pattern after you group the
numbers.
1, 1, 2, 1, 2, 3, 1, 2, 3, 4, (1), (1, 2), (1, 2, 3), (1, 2, 3, 4,),
Index of Term
An index of term indicates the order in which the term appears in a sequence.
For example, consider the sequence: 2, 4, 6, 8, 10,
The 3rd term 6 has an index of 3. The index of 6 is 3.
The 4th term 8 has an index of 4. The index of 8 is 4.
Example The sequence below follows a certain pattern. Find the 50th term.
1, 2, 3, 2, 3, 4, 3, 4, 5, 4, 5, 6,
Class Notes
Group the sequence by putting three numbers in each group.
(1, 2, 3), (2, 3, 4), (3, 4, 5), (4, 5, 6),
As each group contains three numbers, the multiple of 3 that is closest to but
smaller than 50 is 3 3 33 .
16 terms .
So the 50th term of this sequence is the second number of group
Since the first number of each group starts from 1 and increases by 1, the first number
of group 17 is . Since the numbers of each group increase by 1 from the first
number, the second number of group 17 is .
Therefore, the 50th term is .
Try It Again Find the 20th term of the sequence.
1, 2, 3, 3, 4, 5, 5, 6, 7,
87Rules and Numbers
