Here are examples of number patterns suitable for Grade 8, drawn from the provided sequences. These sequences illustrate different types of patterns, from simple arithmetic to geometric and more complex patterns.
Examples of Number Patterns for Grade 8
Below are several examples of number patterns, explained for Grade 8 students.
Arithmetic Sequences
Arithmetic sequences are number patterns where the difference between consecutive terms is constant.
-
Sequence A: 2; 5; 8; 11; 14; 17; 20; 23;
- Here, the common difference is 3. Each number is 3 more than the previous one (e.g., 5-2=3, 8-5=3, 11-8=3). This can be expressed as
a_n = 2 + 3(n-1)
, wherea_n
is the nth term in the sequence.
- Here, the common difference is 3. Each number is 3 more than the previous one (e.g., 5-2=3, 8-5=3, 11-8=3). This can be expressed as
-
Sequence G: 1; 5; 9; 13; 17; 21; 25; 29; 33;
- The common difference is 4. Each number is 4 more than the one before it (e.g., 5-1=4, 9-5=4, 13-9=4). This sequence can be defined as
a_n = 1 + 4(n-1)
.
- The common difference is 4. Each number is 4 more than the one before it (e.g., 5-1=4, 9-5=4, 13-9=4). This sequence can be defined as
Geometric Sequences
Geometric sequences involve a constant ratio between consecutive terms.
- Sequence C: 1; 2; 4; 8; 16; 32; 64;
- Here, the common ratio is 2. Each number is twice the previous one (e.g., 2/1=2, 4/2=2, 8/4=2). The rule for this is
a_n = 1 * 2^(n-1)
.
- Here, the common ratio is 2. Each number is twice the previous one (e.g., 2/1=2, 4/2=2, 8/4=2). The rule for this is
- Sequence H: 2; 4; 8; 16; 32; 64;
- The common ratio is 2. Each number is double the one before (e.g., 4/2=2, 8/4=2, 16/8=2). The formula is
a_n = 2 * 2^(n-1)
which is alsoa_n = 2^n
.
- The common ratio is 2. Each number is double the one before (e.g., 4/2=2, 8/4=2, 16/8=2). The formula is
- Sequence F: 2; 6; 18; 54; 162; 486;
- The common ratio is 3. Each number is three times the previous one (e.g., 6/2=3, 18/6=3, 54/18=3). This can be shown as
a_n = 2 * 3^(n-1)
.
- The common ratio is 3. Each number is three times the previous one (e.g., 6/2=3, 18/6=3, 54/18=3). This can be shown as
Sequences with More Complex Patterns
These patterns involve differences that are not constant.
- Sequence B: 4; 5; 8; 13; 20; 29; 40;
- The differences between terms are 1, 3, 5, 7, 9, 11... which is a pattern of adding consecutive odd numbers.
- Sequence E: 4; 5; 7; 10; 14; 19; 25; 32; 40;
- The differences between terms are 1, 2, 3, 4, 5, 6, 7, 8... which is a pattern of adding consecutive natural numbers.
Understanding Number Patterns
- Analyzing the differences: Look at the difference between consecutive numbers. If it's constant, it's arithmetic.
- Checking the ratio: If the ratio between consecutive numbers is constant, it's geometric.
- Finding the rule: Determine the underlying rule or formula that generates the sequence to find any term.
These examples demonstrate various number patterns that are appropriate for Grade 8 mathematics.