Mathematics·Algebra·procedural
Nth-Term Rules
Find the nth-term expression for an arithmetic sequence by identifying the common difference and the zero-term, and use it to determine any term in the sequence or test whether a given number belongs to the sequence
Suggested ages 12–14
Evidence of understanding
- Derive the nth-term rule for an arithmetic sequence such as 3, 7, 11, 15, … as 4n − 1
- Use an nth-term formula to find the 50th or 100th term without listing all preceding terms
- Determine whether a given number (e.g., 99) is a term in a specified arithmetic sequence
Assessment prompt
If Nth-Term Rules is given the sequence 4, 7, 10, 13…, can they find a formula for the nth term — and use it to check whether, say, 100 is in the sequence?
Standards alignment
8.F.4US · ccss-math
Constructing linear functions
Common Core State Standards for Mathematics · 8
KS3.Maths.Alg.15GB · uk-nc-2013
Arithmetic Sequences
The national curriculum in England: Key stages 1 and 2 framework document · Key Stage 3